Get Information about IPv6 Addresses with IPNetInfo

<a href="http://ipv4-ipv6.blogspot.com/" target="_blank">IPNetInfo</a> is a small freeware utility that allows you to easily find all available information about an IP address. It can fetch you the details like the owner of the IP address, the country/state name, IP addresses range, contact information (address, phone, fax, and email), and more. Now that the Internet is moving towards IPv6 addresses,  the new version of IPNetInfo, you can even get the details of IPv6 addresses.<br /> <br /> <img class="img" src="http://external-sin.xx.fbcdn.net/safe_image.php?d=AQDJJQ_v9xUueIO6&url=http%3A%2F%2Fcdn.nirmaltv.com%2Fimages%2Fipnetinfo_ipv61.png" /><br /> <br /> In order to use this feature in the app, you have to check the ‘Detect IPv6 Addresses’ option in the ‘Choose IP addresses’ window. This option is disabled by default when you run the application. After enabling this feature, you can type one or more IPv6 addresses in the addresses list text-box, and then the result looks like in the image above.<br /> <br /> The IP address information is retrieved by sending a request to the whois server. The program uses multiple Whois servers, so in case one is not able to retrieve the information, the app uses the other ones available.<br /> <br /> <a href="http://www.liutilities.com/affcb/?id=RBgen&aff=4894&xat=NirmaltvRBArticleHeader" rel="nofollow" target="_blank"><img class="img" src="http://external-sin.xx.fbcdn.net/safe_image.php?d=AQDS3ibiSBGAbsRg&url=http%3A%2F%2Fcdn.nirmaltv.com%2Fimages%2FAd68.gif" /></a><br /> <br /> <a href="http://pt-pt.facebook.com/l.php?u=http%3A%2F%2Fwww.nirsoft.net%2Futils%2Fipnetinfo.html&h=eAQF7YZdk&s=1" rel="nofollow" target="_blank">Download IPNetInfo</a>

Get Information about IPv6 Addresses with IPNetInfo

Tukiyooo 1 01:44

IPNetInfo is a small freeware utility that allows you to easily find all available information about an IP address. It can fetch you the details like the owner of the IP address, the country/state name, IP addresses range, contact information (ad… Read more »

Read more »

How To Disable IPv6 In Ubuntu 10.04 Lucid Lynx ?

<div> I'm not sure if IPv6 in Ubuntu 10.04 Lucid Lynx is still causing issues with the Internet connection being slow and so on, but in case it does here's how to disable it.</div> <br /><a href="https://www.facebook.com/note.php?note_id=392223309742#" role="button"></a><br /> <div> To check if IPv6 is disabled, run the following command:<br /><pre class=""><code>cat /proc/sys/net/ipv6/conf/all/disable_ipv6</code></pre> <br />0 means it's enabled and 1 - disabled.<br /><br /><br />This tweak is thanks to an old comment from <a href="http://l.facebook.com/l.php?u=http%3A%2F%2Fwww.webupd8.org%2F2009%2F11%2Fhow-to-disable-ipv6-in-ubuntu-910.html%23comment-26954313&h=GAQHSEos9&s=1" rel="nofollow" target="_blank">Stonecut</a> (this way you don't have to edit the GRUB). Basically, to disable IPv6 in Ubuntu 10.04 Lucid Lynx, you have to add the following lines to /etc/sysctl.conf:<br /><br /><blockquote> #disable ipv6<br />net.ipv6.conf.all.disable_ipv6 = 1<br />net.ipv6.conf.default.disable_ipv6 = 1<br />net.ipv6.conf.lo.disable_ipv6 = 1</blockquote> <br /><br />To do it from the command line, paste this in a terminal:<br /><pre class=""><code>echo "#disable ipv6" | sudo tee -a /etc/sysctl.conf echo "net.ipv6.conf.all.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf echo "net.ipv6.conf.default.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf echo "net.ipv6.conf.lo.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf</code></pre> <br /><br />Then reboot and check if IPv6 has been disabled with the command in the beginning of the post.<br /><br /><br />If for some reason IPv6 still shows up as enabled in Ubuntu 10.04 Lucid Lynx, you can use the method described in THIS post.<br /><br /><br />This tweak (and others) will go into Ubuntu 10.04 Start script (I don't know why I didn't think of this before).</div> <div class=""> <div class=""> <hr size="2" />© <a href="http://l.facebook.com/l.php?u=http%3A%2F%2Fwww.webupd8.org%2F&h=CAQG7mfD3&s=1" rel="nofollow" target="_blank"></a><a href="http://l.facebook.com/l.php?u=http%3A%2F%2Fwww.webupd8.org%2F&h=QAQHVMxzP&s=1" rel="nofollow" target="_blank">www.webupd8.org</a> 2009-2010. | What's New on the World Wide Web</div> <div class=""> <br /></div> <div class=""> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/how-to-disable-ipv6-in-ubuntu-1004.html">http://ipv4-ipv6.blogspot.com/2014/07/how-to-disable-ipv6-in-ubuntu-1004.html</a></span></div> </div>

How To Disable IPv6 In Ubuntu 10.04 Lucid Lynx ?

Tukiyooo 1 01:40

I'm not sure if IPv6 in Ubuntu 10.04 Lucid Lynx is still causing issues with the Internet connection being slow and so on, but in case it does here's how to disable it. To check if IPv6 is disabled, run the following command:cat /proc/sys/net/ipv6… Read more »

Read more »

IPv6 for Enterprise Networks

The practical guide to deploying IPv6 in campus,<br /> WAN/branch, data center, and virtualized environments<br /> IPv6 for Enterprise Networks brings together all the information you need to successfully deploy IPv6 in any campus, WAN/branch, data center, or virtualized environment. Four leading Cisco IPv6 experts present a practical approach to organizing and executing your large-scale IPv6 implementation. They show how IPv6 affects existing network designs, describe common IPv4/IPv6 coexistence mechanisms, guide you in planning, and present validated configuration examples for building labs, pilots, and production networks.<br /> <br /> The authors first review some of the drivers behind the acceleration of IPv6 deployment in the enterprise. Next, they introduce powerful new IPv6 services for routing, QoS, multicast, and management, comparing them with familiar IPv4 features and behavior. Finally, they translate IPv6 concepts into usable configurations. Up-to-date and practical, IPv6 for Enterprise Networks is an indispensable resource for every network engineer, architect, manager, and consultant who must evaluate, plan, migrate to, or manage IPv6 networks.<br /> <br /> Shannon McFarland, CCIE No. 5245, is a Corporate Consulting Engineer for Cisco serving as a technical consultant for enterprise IPv6 deployment and data center design with a focus on application deployment and virtual desktop infrastructure. For more than 16 years, he has worked on large-scale enterprise campus, WAN/branch, and data center network design and optimization. For more than a decade, he has spoken at IPv6 events worldwide, including Cisco Live.<br /> <br /> <br /> n    Identify how IPv6 affects enterprises<br /> <br /> <br /> n    Understand IPv6 services and the IPv6 features that make them possible<br /> <br /> <br /> n    Review the most common tranisition mechanisms including dual-stack (IPv4/IPv6) networks, IPv6 over IPv4 tunnels, and IPv6 over MPLS<br /> <br /> <br /> n    Create IPv6 network designs that reflect proven principles of modularity, hierarchy, and resiliency<br /> <br /> <br /> n    Select the best implementation options for your organization<br /> <br /> <br /> n    Build IPv6 lab environments<br /> <br /> <br /> n    Configure IPv6 step-by-step in campus, WAN/branch, and data center networks<br /> <br /> <br /> n    Integrate production-quality IPv6 services into IPv4 networks<br /> <br /> <br /> n    Implement virtualized IPv6 networks<br /> <br /> <br /> n    Deploy IPv6 for remote access<br /> <br /> <br /> n    Manage IPv6 networks efficiently and cost-effectively<br /> <br /> <br /> This book is part of the Networking Technology Series from Cisco Press®, which offers networking professionals valuable information for constructing efficient networks, understanding new technologies, and building successful careers.<br /> <br /> <br /> <a href="http://lm.facebook.com/l.php?u=http%3A%2F%2Fwww.filesonic.com%2Ffile%2F903986834%2Fsharebookfree.com_824597592.rar&h=XAQF2oj3z&s=1" rel="nofollow" target="_blank">http://www.filesonic.com/file/903986834/sharebookfree.com_824597592.rar</a><br /> <br />  <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/the-practical-guide-to-deploying-ipv6.html">http://ipv4-ipv6.blogspot.com/2014/07/the-practical-guide-to-deploying-ipv6.html</a></span><br /> <br /> <br /> <span class="photo "><img class="img" data-store="{"imgsrc":"https:\/\/scontent-b.xx.fbcdn.net\/hphotos-xpf1\/t1.0-0\/p280x280\/230103_203779679657839_2904226_n.jpg"}" height="280" src="https://scontent-b.xx.fbcdn.net/hphotos-xpf1/t1.0-0/p280x280/230103_203779679657839_2904226_n.jpg" width="280" /></span>

IPv6 for Enterprise Networks

Tukiyooo 0 01:38

The practical guide to deploying IPv6 in campus, WAN/branch, data center, and virtualized environments IPv6 for Enterprise Networks brings together all the information you need to successfully deploy IPv6 in any campus, WAN/branch, data center, or … Read more »

Read more »

IPv6 Mobility

When a host is connected to one link or network, it acquires an IP address and all communication happens using that IP address on that link. As soon as, the same host changes its physical location, that is, moves into some different area / subnet / network / link, its IP address changes accordingly and all communication happening on the host using old IP address, goes down.<br /> IPv6 mobility provides a mechanism which equips a host with an ability to roam around among different links without losing any communication/connection and its IP address.<br /> Multiple entities are involved in this technology:<br /> <ul class="list"> <li><b>Mobile Node</b>: The device which needs IPv6 mobility. </li> <li><b>Home Link</b>: This link is configured with the home subnet prefix and this is where the Mobile IPv6 device gets its Home Address.</li> <li><b>Home Address</b>: This is the address which Mobile Node acquires from Home Link. This is permanent address of Mobile Node. If the Mobile Node remains in the same Home Link, the communication among various entities happens as usual.</li> <li><b>Home Agent</b>: This is a router which acts as registrar for Mobile Nodes. Home Agent is connected to Home Link and maintains information about all Mobile Nodes, their Home Addresses and their present IP addresses.</li> <li><b>Foreign Link</b>: Any other Link which is not Mobile Node’s Home Link.</li> <li><b>Care-of Address</b>: When a Mobile Node attaches to a Foreign Link, it acquires a new IP address of that Foreign Link’s subnet. Home Agent maintains the information of both Home Address and Care-of Address. Multiple Care-of addresses can be assigned to Mobile Node, but at any instance only one Care-of Address has binding with Home Address.</li> <li><b>Correspondent Node</b>: Any IPv6 enable device which intends to have communication with Mobile Node.</li> </ul> <h2> Mobility Operation</h2> When Mobile Node stays in its Home Link, all communications happen on its Home Address. As shown below:<br /> <figure> <img caption="Mobile Node in Home Link" src="http://www.tutorialspoint.com/ipv6/images/MN_in_HL.jpg" /> <figcaption align="center">[<i>Image: Mobile Node connected to Home Link</i>]</figcaption> </figure>When Mobile Node leaves its Home Link and is connected to some Foreign Link, the Mobility feature of IPv6 comes into play. After connecting to Foreign Link, Mobile Node acquires an IPv6 address from Foreign Link. This address is called Care-of Address. Mobile Node sends binding request to its Home Agent with the new Care-of Address. Home Agent binds Mobile Node’s Home Address with Care-of Address, establishing a Tunnel between both.<br /> Whenever a Correspondent Node tries to establish connection with Mobile Node (on its Home Address), the Home Agent intercepts the packet and forwards to Mobile Node’s Care-of Address over the Tunnel which was already established.<br /> <figure> <img caption="Mobile Node in Foreign Link" src="http://www.tutorialspoint.com/ipv6/images/MN_in_FL.jpg" /> <figcaption align="center">[<i>Image: Mobile Node connected to Foreign Link</i>]</figcaption> </figure><h2> Route Optimization</h2> <br /> When a Correspondent Node initiate communication by sending packets to Mobile Node on Home Address, these packets are tunneled to Mobile Node by Home Agent. In Route Optimization mode, when the Mobile Node receives packet from Correspondent Node, it does not forward replies to Home Agent. Rather it sends its packet directly to Correspondent Node using Home Address as Source Address. This mode is optional and not used by default.<br /> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/when-host-is-connected-to-one-link-or.html">http://ipv4-ipv6.blogspot.com/2014/07/when-host-is-connected-to-one-link-or.html</a></span>

IPv6 Mobility

Tukiyooo 0 01:23

When a host is connected to one link or network, it acquires an IP address and all communication happens using that IP address on that link. As soon as, the same host changes its physical location, that is, moves into some different area / subnet… Read more »

Read more »

IPv6 Subnetting

<a href="http://ipv4-ipv6.blogspot.com/" target="_blank">In IPv4</a>, addresses were created in classes. Classful IPv4 addresses clearly defines the bits used for network prefixes and the bits used for hosts on that network. To subnet in IPv4 we play with the default classful netmask which allows us to borrow hosts bit to be used as subnet bits. This results in multiple subnets but less hosts per subnet. That is, when we borrow host bit to create a subnet that costs us in lesser bit to be used for host addresses.<br /> IPv6 addresses uses 128 bits to represent an address which includes bits to be used for subnetting. Second half of the address (least significant 64 bits) is always used for Hosts only. Therefore, there is no compromise if we subnet the network.<br /> <figure> <img caption="IPv6 Subnetting" src="http://www.tutorialspoint.com/ipv6/images/subnetting.jpg" /> <figcaption align="center">[<i>Image: IPv6 Subnetting</i>]</figcaption> </figure>16 Bits of subnet is equivalent to IPv4’s Class B Network. Using these subnet bits an organization can have more 65 thousands of subnets which is by far, more than enough.<br /> Thus routing prefix is /64 and host portion is 64 bits. We though, can further subnet the network beyond 16 bits of Subnet ID, borrowing hosts bit but it is recommended that 64 bits should always be used for hosts addresses because auto-configuration requires 64 bits.<br /> IPv6 subnetting works on the same concept as Variable Length Subnet Masking in IPv4.<br /> <br /> /48 prefix can be allocated to an organization providing it the benefit of having up to /64 subnet prefixes, which is 65535 sub-networks, each having 264 hosts. A /64 prefix can be assigned to a point-to-point connection where there are only two hosts (or IPv6 enabled devices) on a link.

IPv6 Subnetting

Tukiyooo 0 01:21

In IPv4, addresses were created in classes. Classful IPv4 addresses clearly defines the bits used for network prefixes and the bits used for hosts on that network. To subnet in IPv4 we play with the default classful netmask which allows us to bo… Read more »

Read more »

IPv6 Summary

<a href="http://ipv4-ipv6.blogspot.com/" target="_blank">IPv4 since 1982</a>, has been an undisputed leader of Internet. With IPv4’s address space exhaustion IPv6 is now taking over the control of Internet, which is called Internet2.<br /> IPv4 is widely deployed and migration to IPv6 would not be easy. So far IPv6 could penetrate IPv4’s address space by less than 1%. <br /> The world has celebrated ‘World IPv6 Day’ on June 08, 2011 with a purpose to test IPv6 address over Internet in full. On June 06, 2012 the Internet community officially launched IPv6. This day all ISPs who were offering IPv6 were to enable it on public domain and were to keep it enable. All the device manufacturer also participated to offer IPv6 by-default enabled on devices.<br /> This was a step towards encouraging Internet community to migrate to IPv6.<br /> Organizations are provided plenty of ways to migrate from IPv4 to IPv6. Also organization, willing to test IPv6 before migrating completely can run both IPv4 and IPv6 simultaneously. Networks of different IP versions can communicate and user data can be tunneled to walk to the other side.<br /> <h2> Future of IPv6</h2> IPv6 enabled Internet version 2 will replace todays IPv4 enabled Internet. When Internet was launched with IPv4, developed countries like US and Europe took the larger space of IPv4 for deployment of Internet in their respective countries keeping future need in mind. But Internet exploded everywhere reaching and connecting every country of the world increasing the requirement of IPv4 address space. As a result, till this day US and Europe have many IPv4 address space left with them and countries like India and China are bound to address their IP space requirement by means of deployment of IPv6.<br /> Most of the IPv6 deployment is being done outside US, Europe. India and China are moving forward to change their entire space to IPv6. China has announced a five year deployment plan named China Next Generation Internet.<br /> After June 06, 2012 all major ISPs were shifted to IPv6 and rest of them are still moving.<br /> <br /> IPv6 provides ample of address space and is designed to expand today’s Internet services. Feature-rich IPv6 enabled Internet version 2 may deliver more than expected.<br /> <br /> <div class="GCUXF0KCCXB" style="background-color: #edf4ff; border: 0px; color: #888888; cursor: default; font-family: Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 0px; vertical-align: baseline; word-wrap: break-word;"> <a href="http://ipv4-ipv6.blogspot.com/2014/07/ipv6-summary.html">http://ipv4-ipv6.blogspot.com/2014/07/ipv6-summary.html</a></div> <div> <br /></div>

IPv6 Summary

Tukiyooo 0 01:20

IPv4 since 1982, has been an undisputed leader of Internet. With IPv4’s address space exhaustion IPv6 is now taking over the control of Internet, which is called Internet2. IPv4 is widely deployed and migration to IPv6 would not be easy. So far … Read more »

Read more »

IPv6 Routing

Routing concepts remain same in case of <a href="http://ipv4-ipv6.blogspot.com/" target="_blank">IPv6</a> but almost all routing protocol have been redefined accordingly. We have seen in Communication in IPv6 segment, how a host speaks to its gateway. Routing is a process to forward routable data choosing best route among several available routes or path to the destination. A router is a device which forwards data which is not explicitly destined to it.<br /> There exists two forms of routing protocols<br /> <ul class="list"> <li><b>Distance Vector Routing Protocol</b>: A router running distance vector protocol advertises its connected routes and learns new routes from its neighbors. The routing cost to reach a destination is calculated by means of hops between the source and destination. A Router generally relies on its neighbor for best path selection, also known as “routing-by-rumors”. RIP and BGP are Distance Vector Protocols.</li> <li><b>Link-State Routing Protocol</b>: This protocol acknowledges the state of a Link and advertises to its neighbors. Information about new links is learnt from peer routers. After all the routing information has been converged, Link-State Routing Protocol uses its own algorithm to calculate best path to all available links. OSPF and IS-IS are link state routing protocols and both uses Djikstra’s Shortest Path First algorithm.</li> </ul> Routing protocols can be divided in two categories:<br /> <ul class="list"> <li><b>Interior Routing Protocol</b>: Protocols in this categories are used within an Autonomous System or organization to distribute routes among all routers inside its boundary. Examples: RIP, OSPF.</li> <li><b>Exterior Routing Protocol</b>: Whereas an Exterior Routing Protocol distributes routing information between two different Autonomous Systems or organization. Examples: BGP.</li> </ul> <h2> Routing protocols</h2> <ul class="list"> <li><b>RIPng</b><br /> RIPng stands for Routing Information Protocol Next Generation. This is an Interior Routing Protocol and is a Distance Vector Protocol. RIPng has been upgraded to support IPv6.<br /> </li> <li><b>OSPFv3</b></li> Open Shortest Path First version 3 is an Interior Routing Protocol which is modified to support IPv6. This is a Link-State Protocol and uses Djikrasta’s Shortest Path First algorithm to calculate best path to all destinations.<br /> <li><b>BGPv4</b><br /> BGP stands for Border Gateway Protocol. It is the only open standard Exterior Gateway Protocol available. BGP is a Distance Vector protocol which takes Autonomous System as calculation metric, instead of number of routers as Hop. BGPv4 is an upgrade of BGP to support IPv6 routing.</li> </ul> <h2> Protocols changed to support IPv6:</h2> <br /> <ul class="list"> <li><b>ICMPv6</b>: Internet Control Message Protocol version 6 is an upgraded implementation of ICMP to accommodate IPv6 requirements. This protocol is used for diagnostic functions, error and information message, statistical purposes. ICMPv6’s Neighbor Discovery Protocol replaces ARP and helps discover neighbor and routers on the link.</li> <li><b>DHCPv6</b>: Dynamic Host Configuration Protocol version 6 is an implementation of DHCP. Though IPv6 enabled hosts do not require any DHCPv6 Server to acquire IP address as they can be auto-configured. Neither do they need DHCPv6 to locate DNS server because DNS can be discovered and configured via ICMPv6 Neighbor Discovery Protocol. Yet DHCPv6 Server can be used to provide these information. </li> <li><b>DNS</b>: There has been no new version of DNS but it is now equipped with extensions to provide support for querying IPv6 addresses. A new AAAA (quad-A) record has been added to reply IPv6 query messages. Now DNS can reply with both IP versions (4 & 6) without any change in query format.</li> </ul> <div> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/ipv6-routing.html">http://ipv4-ipv6.blogspot.com/2014/07/ipv6-routing.html</a></span></div> <div> <br /></div>

IPv6 Routing

Tukiyooo 0 01:18

Routing concepts remain same in case of IPv6 but almost all routing protocol have been redefined accordingly. We have seen in Communication in IPv6 segment, how a host speaks to its gateway. Routing is a process to forward routable data choosing… Read more »

Read more »

Address Types & Formats IPv6

<h2> Hexadecimal Number System</h2> Before introducing <a href="http://ipv4-ipv6.blogspot.com/" target="_blank">IPv6 Address format</a>, we shall look into Hexadecimal Number System. Hexadecimal is positional number system which uses radix (base) of 16. To represent the values in readable format, this system uses 0-9 symbols to represent values from zero to nine and A-F symbol to represent values from ten to fifteen. Every digit in Hexadecimal can represent values from 0 to 15.<br /> <figure> <img caption="Hexadecimal Conversion Table" src="http://www.tutorialspoint.com/ipv6/images/Hexadecimal_conversion_table.jpg" /> <figcaption align="center">[<i>Image: Conversion Table</i>]</figcaption> </figure><h2> Address Structure</h2> An IPv6 address is made of 128 bits divided into eight 16-bits blocks. Each block is then converted into 4-digit Hexadecimal numbers separated by colon symbol.<br /> For example, the below is 128 bit IPv6 address represented in binary format and divided into eight 16-bits blocks:<br /> <blockquote> 0010000000000001 0000000000000000 0011001000110100 1101111111100001 0000000001100011 0000000000000000 0000000000000000 1111111011111011</blockquote> Each block is then converted into Hexadecimal and separated by ‘:’ symbol:<br /> <blockquote> 2001:0000:3238:DFE1:0063:0000:0000:FEFB</blockquote> Even after converting into Hexadecimal format, IPv6 address remains long. IPv6 provides some rules to shorten the address. These rules are:<br /> <b>Rule:1</b> Discard leading Zero(es):<br /> In Block 5, 0063, the leading two 0s can be omitted, such as (5th block):<br /> <blockquote> 2001:0000:3238:DFE1:63:0000:0000:FEFB</blockquote> <b>Rule:2</b> If two of more blocks contains consecutive zeroes, omit them all and replace with double colon sign ::, such as (6th and 7th block):<br /> <blockquote> 2001:0000:3238:DFE1:63::FEFB</blockquote> Consecutive blocks of zeroes can be replaced only once by :: so if there are still blocks of zeroes in the address they can be shrink down to single zero, such as (2nd block):<br /> <blockquote> 2001:0:3238:DFE1:63::FEFB</blockquote> <h2> Interface ID</h2> IPv6 has three different type of Unicast Address scheme. The second half of the address (last 64 bits) is always used for Interface ID. MAC address of a system is composed of 48-bits and represented in Hexadecimal. MAC address is considered to be uniquely assigned worldwide. Interface ID takes advantage of this uniqueness of MAC addresses. A host can auto-configure its Interface ID by using IEEE’s Extended Unique Identifier (EUI-64) format. First, a Host divides its own MAC address into two 24-bits halves. Then 16-bit Hex value 0xFFFE is sandwiched into those two halves of MAC address, resulting in EUI-64 Interface ID.<br /> <img src="http://www.tutorialspoint.com/ipv6/images/interface_id.jpg" /> <br /> <figcaption align="center">[<i>Image: EUI-64 Interface ID</i>]</figcaption><b>Conversion of EUI-64 ID into IPv6 Interface Identifier</b><br /> To convert EUI-64 ID into IPv6 Interface Identifier, the most significant 7^{<small>th</small>} bit of EUI-64 ID is complemented. For example:<br /> <figure style="margin: 0px; padding: 0px;"> <img src="http://www.tutorialspoint.com/ipv6/images/eui_to_ipv6_id.png" /> <figcaption align="center">[<i>Image: IPV6 Interface ID</i>]</figcaption> </figure><h2> Global Unicast Address</h2> This address type is equivalent to IPv4’s public address. Global Unicast addresses in IPv6 are globally identifiable and uniquely addressable. <br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Global Unicast Address" src="http://www.tutorialspoint.com/ipv6/images/global_unicast_address.jpg" /> <figcaption align="center">[<i>Image: Global Unicast Address</i>]</figcaption> </figure>Global Routing Prefix: The most significant 48-bits are designated as Global Routing Prefix which is assigned to specific Autonomous System. Three most significant bits of Global Routing Prefix is always set to 001.<br /> <h2> Link-Local Address</h2> Auto-configured IPv6 address is known as Link-Local address. This address always starts with FE80. First 16 bits of Link-Local address is always set to 1111 1110 1000 0000 (FE80). Next 48-bits are set to 0, thus:<br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Link-Local Address" src="http://www.tutorialspoint.com/ipv6/images/link_local_address.jpg" /> <figcaption align="center">[<i>Image: Link-Local Address</i>]</figcaption> </figure>Link-Local addresses are used for communication among IPv6 hosts on a link (broadcast segment) only. These addresses are not routable so a Router never forwards these addresses outside the link.<br /> <h2> Unique-Local Address</h2> This type of IPv6 address which is though globally unique, but it should be used in local communication. This address has second half of Interface ID and first half is divided among Prefix, Local Bit, Global ID and Subnet ID.<br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Unique-Local Address" src="http://www.tutorialspoint.com/ipv6/images/unique_local_address.jpg" /> <figcaption align="center">[<i>Image: Unique-Local Address</i>]</figcaption> </figure> Prefix is always set to 1111 110. L bit, which is set to 1 if the address is locally assigned. So far the meaning of L bit to 0 is not defined. Therefore, Unique Local IPv6 address always starts with ‘FD’. <br /> <h3> Scope of IPv6 Unicast Addresses:</h3> <figure> <img caption="IPv6 Unicast Address Scope" src="http://www.tutorialspoint.com/ipv6/images/address_scope.jpg" /> <figcaption align="center">[<i>Image: IPv6 Unicast Address Scope</i>]</figcaption> </figure> <br /> The scope of Link-local address is limited to the segment. Unique Local Address are though locally global but are not routed over the Internet, limiting their scope to an organization’s boundary. Global Unicast addresses are globally unique and recognizable. They shall make the essence of Internet v2 addressing.<br /> <br /> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/address-types-formats-ipv6.html">http://ipv4-ipv6.blogspot.com/2014/07/address-types-formats-ipv6.html</a></span>

Address Types & Formats IPv6

Tukiyooo 0 01:17

Hexadecimal Number System Before introducing IPv6 Address format, we shall look into Hexadecimal Number System. Hexadecimal is positional number system which uses radix (base) of 16. To represent the values in readable format, this system uses … Read more »

Read more »

IPv6 Addressing Modes

<a href="http://ipv4-ipv6.blogspot.com/" target="_blank">In computer networking</a>, addressing mode refers to the mechanism how we address a host on the network. IPv6 offers several types of modes by which a single host can be addressed, more than one host can be addressed at once or the host at closest distance can be addressed.<br /> <h2> Unicast</h2> In unicast mode of addressing, an IPv6 interface (host) is uniquely identified in a network segment. The IPv6 packet contains both source and destination IP addresses. A host interface is equipped with an IP address which is unique in that network segment. A network switch or router when receives a unicast IP packet, destined to single host, sends out to one of its outgoing interface which connects to that particular host.<br /> <figure> <img caption="Unicast Messaging" src="http://www.tutorialspoint.com/ipv6/images/unicast.jpg" /> <figcaption align="center">[<i>Image: Unicast Messaging</i>]</figcaption> </figure><h2> Multicast</h2> The IPv6 multicast mode is same as that of IPv4. The packet destined to multiple hosts is sent on a special multicast address. All hosts interested in that multicast information, need to join that multicast group first. All interfaces which have joined the group receive the multicast packet and process it, while other hosts not interested in multicast packets ignore the multicast information.<br /> <figure> <img caption="Multicast Messaging" src="http://www.tutorialspoint.com/ipv6/images/multicast.jpg" /> <figcaption align="center">[<i>Image: Multicast Messaging</i>]</figcaption> </figure><h2> Anycast</h2> IPv6 has introduced a new type of addressing, which is called Anycast addressing. In this addressing mode, multiple interfaces (hosts) are assigned same Anycast IP address. When a host wishes to communicate with a host equipped with an Anycast IP address, sends a Unicast message. With the help of complex routing mechanism, that Unicast message is delivered to the host closest to the Sender, in terms of Routing cost.<br /> <figure> <img caption="Anycast Messaging" src="http://www.tutorialspoint.com/ipv6/images/anycast.jpg" /> <figcaption align="center">[<i>Image: Anycast Messaging</i>]</figcaption> </figure>Let’s take an example of TutorialPoints.com Web Servers, located in all continents. Assume that all Web Servers are assigned single IPv6 Anycast IP Address. Now when a user from Europe wants to reach TutorialsPoint.com the DNS points to the server which is physically located in Europe itself. If a user from India tries to reach Tutorialspoint.com, the DNS will then point to Web Server physically located in Asia only. Nearest or Closest terms are used in terms of Routing Cost.<br /> <br /> In the above picture, When a client computer tries to reach a Server, the request is forwarded to the Server with lowest Routing Cost.<br /> <br /> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/in-computer-networking-addressing-mode.html">http://ipv4-ipv6.blogspot.com/2014/07/in-computer-networking-addressing-mode.html</a></span>

IPv6 Addressing Modes

Tukiyooo 0 01:15

In computer networking, addressing mode refers to the mechanism how we address a host on the network. IPv6 offers several types of modes by which a single host can be addressed, more than one host can be addressed at once or the host at closest d… Read more »

Read more »

IPv6 - Headers

The wonder of IPv6 lies in its header. IPv6 address is 4 times larger than IPv4 but the IPv6 header is only 2 times larger than that of IPv4. IPv6 headers have one Fixed Header and zero or more Optional (Extension) Headers. All necessary information which is essential for a router is kept in Fixed Header. Extension Header contains optional information which helps routers to understand how to handle a packet/flow.<br /> <h2> <a href="http://ipv4-ipv6.blogspot.com/" target="_blank">Fixed Header</a></h2> <figure style="margin: 0px; padding: 0px;"> <img caption="IPv6 Fixed Header" src="http://www.tutorialspoint.com/ipv6/images/IPv6_header.jpg" /> <figcaption align="center">[<i>Image: IPv6 Fixed Header</i>]</figcaption> </figure>IPv6 fixed header is 40 bytes long and contains the following information.<br /> <table class="src"> <tbody> <tr><th style="width: 5%;">S.N.</th><th>Field & Description</th></tr> <tr><td>1</td><td><b>Version</b> (4-bits): This represents the version of Internet Protocol, i.e. 0110.</td></tr> <tr><td>2</td><td><b>Traffic Class</b> (8-bits): These 8 bits are divided into two parts. Most significant 6 bits are used for Type of Service, which tells the Router what services should be provided to this packet. Least significant 2 bits are used for Explicit Congestion Notification (ECN).</td></tr> <tr><td>3</td><td><b>Flow Label</b> (20-bits): This label is used to maintain the sequential flow of the packets belonging to a communication. The source labels the sequence which helps the router to identify that this packet belongs to a specific flow of information. This field helps to avoid re-ordering of data packets. It is designed for streaming/real-time media.</td></tr> <tr><td>4</td><td><b>Payload Length</b> (16-bits): This field is used to tell the routers how much information this packet contains in its payload. Payload is composed of Extension Headers and Upper Layer data. With 16 bits, up to 65535 bytes can be indicated but if Extension Headers contain Hop-by-Hop Extension Header than payload may exceed 65535 bytes and this field is set to 0.</td></tr> <tr><td>5</td><td><b>Next Header</b> (8-bits): This field is used to indicate either the type of Extension Header, or if Extension Header is not present then it indicates the Upper Layer PDU. The values for the type of Upper Layer PDU is same as IPv4’s.</td></tr> <tr><td>6</td><td><b>Hop Limit</b> (8-bits): This field is used to stop packet to loop in the network infinitely. This is same as TTL in IPv4. The value of Hop Limit field is decremented by 1 as it passes a link (router/hop). When the field reaches 0 the packet is discarded.</td></tr> <tr><td>7</td><td><b>Source Address</b> (128-bits): This field indicates the address of originator of the packet.</td></tr> <tr><td>8</td><td><b>Destination Address</b> (128-bits): This field provides the address of intended recipient of the packet.</td></tr> </tbody></table> <h2> Extension Headers</h2> In IPv6, the Fixed Header contains only information which is necessary and avoiding information which is either not required or is rarely used. All such information, is put between the Fixed Header and Upper layer header in the form of Extension Headers. Each Extension Header is identified by a distinct value.<br /> When Extension Headers are used, IPv6 Fixed Header’s Next Header field points to the first Extension Header. If there is one more Extension Header, then first Extension Header’s ‘Next-Header’ field point to the second one, and so on. The last Extension Header’s ‘Next-Header’ field point to Upper Layer Header. Thus all headers from point to the next one in a linked list manner.<br /> If the Next Header field contains value 59, it indicates that there’s no header after this header, not even Upper Layer Header.<br /> The following Extension Headers must be supported as per RFC 2460:<br /> <img caption="Extension Headers" src="http://www.tutorialspoint.com/ipv6/images/extension_headers.jpg" /> <br /> The sequence of Extension Headers should be:<br /> <img caption="Extension Headers Sequence" src="http://www.tutorialspoint.com/ipv6/images/extension_headers_sequence.jpg" /> <br /> These headers:<br /> <ul class="list"> <li>1. Should be processed by First and subsequent destinations.</li> <li>2. Should be processed by Final Destination. </li> </ul> Extension Headers are arranged one after another in a Linked list manner, as depicted in the diagram below:<br /> <br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Extension Headers Connection" src="http://www.tutorialspoint.com/ipv6/images/extension_header_sequence.jpg" /> <figcaption align="center">[<i>Image: Extension Headers Connected Format</i>]</figcaption><figcaption align="center"><br /></figcaption><figcaption align="center"><br /></figcaption><figcaption align="center"><span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px; text-align: start;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/the-wonder-of-ipv6-lies-in-its-header.html">http://ipv4-ipv6.blogspot.com/2014/07/the-wonder-of-ipv6-lies-in-its-header.html</a></span></figcaption></figure>

IPv6 - Headers

Tukiyooo 0 01:13

The wonder of IPv6 lies in its header. IPv6 address is 4 times larger than IPv4 but the IPv6 header is only 2 times larger than that of IPv4. IPv6 headers have one Fixed Header and zero or more Optional (Extension) Headers. All necessary inform… Read more »

Read more »

IPv6 Quick Guide

<h1> Overview</h1> <a href="http://ipv4-ipv6.blogspot.com/" target="_blank">Internet Protocol</a> version 6, is a new addressing protocol designed to incorporate whole sort of requirement of future internet known to us as Internet version 2. This protocol as its predecessor IPv4, works on Network Layer (Layer-3). Along with its offering of enormous amount of logical address space, this protocol has ample of features which addresses today’s shortcoming of IPv4.<br /> <h2> Why new IP version?</h2> So far, IPv4 has proven itself as a robust routable addressing protocol and has served human being for decades on its best-effort-delivery mechanism. It was designed in early 80’s and did not get any major change afterward. At the time of its birth, Internet was limited only to a few Universities for their research and to Department of Defense. IPv4 is 32 bits long which offers around 4,294,967,296 (2³²) addresses. This address space was considered more than enough that time. Given below are major points which played key role in birth of IPv6:<br /> <ul class="list"> <li>Internet has grown exponentially and the address space allowed by IPv4 is saturating. There is a requirement of protocol which can satisfy the need of future Internet addresses which are expected to grow in an unexpected manner.</li> <li>Using features such as NAT, has made the Internet discontiguous i.e. one part which belongs to intranet, primarily uses private IP addresses; which has to go through number of mechanism to reach the other part, the Internet, which is on public IP addresses.</li> <li>IPv4 on its own does not provide any security feature which is vulnerable as data on Internet, which is a public domain, is never safe. Data has to be encrypted with some other security application before being sent on Internet.</li> <li>Data prioritization in IPv4 is not up to date. Though IPv4 has few bits reserved for Type of Service or Quality of Service, but they do not provide much functionality.</li> <li>IPv4 enabled clients can be configured manually or they need some address configuration mechanism. There exists no technique which can configure a device to have globally unique IP address.</li> </ul> <h2> Why not IPv5?</h2> Till date, Internet Protocol has been recognized has IPv4 only. Version 0 to 3 were used while the protocol was itself under development and experimental process. So, we can assume lots of background activities remain active before putting a protocol into production. Similarly, protocol version 5 was used while experimenting with stream protocol for internet. It is known to us as Internet Stream Protocol which used Internet Protocol number 5 to encapsulate its datagram. Though it was never brought into public use, but it was already used.<br /> Here is a table of IP version and their use:<br /> <img alt="IPv6 Version Table" src="http://www.tutorialspoint.com/ipv6/images/ip_version_table.jpg" /> <br /> <h2> Brief History</h2> After IPv4’s development in early 80s, the available IPv4 address pool begun to shrink rapidly as the demand of addresses exponentially increased with Internet. Taking pre-cognizance of situation that might arise IETF, in 1994, initiated the development of an addressing protocol to replace IPv4. The progress of IPv6 can be tracked by means of RFC published:<br /> <ul class="list"> <li>1998 – RFC 2460 – Basic Protocol</li> <li>2003 – RFC 2553 – Basic Socket API</li> <li>2003 – RFC 3315 – DHCPv6</li> <li>2004 – RFC 3775 – Mobile IPv6</li> <li>2004 – RFC 3697 – Flow Label Specification</li> <li>2006 – RFC 4291 – Address architecture (revision)</li> <li>2006 – RFC 4294 – Node requirement</li> </ul> June 06, 2012 some of Internet giants chose to put their Servers on IPv6. Presently they are using Dual Stack mechanism to implement IPv6 parallel with IPv4.<br /> <h1> Features</h1> The successor of IPv4 is not designed to be backward compatible. Trying to keep the basic functionalities of IP addressing, IPv6 is redesigned entirely. It offers the following features:<br /> <ul class="list"> <li><b> Larger Address Space: </b><br /> In contrast to IPv4, IPv6 uses 4 times more bits to address a device on the Internet. This much of extra bits can provide approximately 3.4×1038 different combinations of addresses. This address can accumulate the aggressive requirement of address allotment for almost everything in this world. According to an estimate, 1564 addresses can be allocated to every square meter of this earth. </li> <li><b>Simplified Header:</b><br /> IPv6’s header has been simplified by moving all unnecessary information and options (which are present in IPv4 header) to the end of the IPv6 header. IPv6 header is only twice as bigger than IPv4 providing the fact the IPv6 address is four times longer. </li> <li><b>End-to-end Connectivity:</b><br /> Every system now has unique IP address and can traverse through the internet without using NAT or other translating components. After IPv6 is fully implemented, every host can directly reach other host on the Internet, with some limitations involved like Firewall, Organization’s policies, etc.</li> <li><b>Auto-configuration:</b><br /> IPv6 supports both stateful and stateless auto configuration mode of its host devices. This way absence of a DHCP server does not put halt on inter segment communication. </li> <li><b>Faster Forwarding/Routing:</b><br /> Simplified header puts all unnecessary information at the end of the header. All information in first part of the header are adequate for a Router to take routing decision thus making routing decision as quickly as looking at the mandatory header.</li> <li><b>IPSec:</b><br /> Initially it was decided for IPv6 to must have IPSec security, making it more secure than IPv4. This feature has now been made optional.</li> <li><b>No Broadcast:</b><br /> Though Ethernet/Token Ring are considered as broadcast network because they support Broadcasting, IPv6 does not have any Broadcast support anymore left with it. It uses multicast to communicate with multiple hosts. </li> <li><b>Anycast Support:</b><br /> This is another characteristic of IPv6. IPv6 has introduced Anycast mode of packet routing. In this mode, multiple interfaces over the Internet are assigned same Anycast IP address. Routers, while routing, sends the packet to the nearest destination.</li> <li><b>Mobility:</b><br /> IPv6 was designed keeping mobility feature in mind. This feature enables hosts (such as mobile phone) to roam around in different geographical area and remain connected with same IP address. IPv6 mobility feature takes advantage of auto IP configuration and Extension headers.</li> <li><b>Enhanced Priority support:</b><br /> Where IPv4 used 6 bits DSCP (Differential Service Code Point) and 2 bits ECN (Explicit Congestion Notification) to provide Quality of Service but it could only be used if the end-to-end devices support it, that is, the source and destination device and underlying network must support it. <br /> In IPv6, Traffic class and Flow label are used to tell underlying routers how to efficiently process the packet and route it.</li> <li><b>Smooth Transition:</b><br /> Large IP address scheme in IPv6 enables to allocate devices with globally unique IP addresses. This assures that mechanism to save IP addresses such as NAT is not required. So devices can send/receive data between each other, for example VoIP and/or any streaming media can be used much efficiently.<br /> Other fact is, the header is less loaded so routers can make forwarding decision and forward them as quickly as they arrive.</li> <li><b>Extensibility:</b><br /> One of the major advantage of IPv6 header is that it is extensible to add more information in the option part. IPv4 provides only 40-bytes for options whereas options in IPv6 can be as much as the size of IPv6 packet itself.</li> </ul> <h1> Addressing Modes</h1> In computer networking, addressing mode refers to the mechanism how we address a host on the network. IPv6 offers several types of modes by which a single host can be addressed, more than one host can be addressed at once or the host at closest distance can be addressed.<br /> <h2> Unicast</h2> In unicast mode of addressing, an IPv6 interface (host) is uniquely identified in a network segment. The IPv6 packet contains both source and destination IP addresses. A host interface is equipped with an IP address which is unique in that network segment. A network switch or router when receives a unicast IP packet, destined to single host, sends out to one of its outgoing interface which connects to that particular host.<br /> <figure> <img caption="Unicast Messaging" src="http://www.tutorialspoint.com/ipv6/images/unicast.jpg" /> <figcaption align="center">[<i>Image: Unicast Messaging</i>]</figcaption> </figure><h2> Multicast</h2> The IPv6 multicast mode is same as that of IPv4. The packet destined to multiple hosts is sent on a special multicast address. All hosts interested in that multicast information, need to join that multicast group first. All interfaces which have joined the group receive the multicast packet and process it, while other hosts not interested in multicast packets ignore the multicast information.<br /> <figure> <img caption="Multicast Messaging" src="http://www.tutorialspoint.com/ipv6/images/multicast.jpg" /> <figcaption align="center">[<i>Image: Multicast Messaging</i>]</figcaption> </figure><h2> Anycast</h2> IPv6 has introduced a new type of addressing, which is called Anycast addressing. In this addressing mode, multiple interfaces (hosts) are assigned same Anycast IP address. When a host wishes to communicate with a host equipped with an Anycast IP address, sends a Unicast message. With the help of complex routing mechanism, that Unicast message is delivered to the host closest to the Sender, in terms of Routing cost.<br /> <figure> <img caption="Anycast Messaging" src="http://www.tutorialspoint.com/ipv6/images/anycast.jpg" /> <figcaption align="center">[<i>Image: Anycast Messaging</i>]</figcaption> </figure>Let’s take an example of TutorialPoints.com Web Servers, located in all continents. Assume that all Web Servers are assigned single IPv6 Anycast IP Address. Now when a user from Europe wants to reach TutorialsPoint.com the DNS points to the server which is physically located in Europe itself. If a user from India tries to reach Tutorialspoint.com, the DNS will then point to Web Server physically located in Asia only. Nearest or Closest terms are used in terms of Routing Cost.<br /> In the above picture, When a client computer tries to reach a Server, the request is forwarded to the Server with lowest Routing Cost.<br /> <h1> Address Types</h1> <h2> Hexadecimal Number System</h2> Before introducing IPv6 Address format, we shall look into Hexadecimal Number System. Hexadecimal is positional number system which uses radix (base) of 16. To represent the values in readable format, this system uses 0-9 symbols to represent values from zero to nine and A-F symbol to represent values from ten to fifteen. Every digit in Hexadecimal can represent values from 0 to 15.<br /> <figure> <img caption="Hexadecimal Conversion Table" src="http://www.tutorialspoint.com/ipv6/images/Hexadecimal_conversion_table.jpg" /> <figcaption align="center">[<i>Image: Conversion Table</i>]</figcaption> </figure><h2> Address Structure</h2> An IPv6 address is made of 128 bits divided into eight 16-bits blocks. Each block is then converted into 4-digit Hexadecimal numbers separated by colon symbol.<br /> For example, the below is 128 bit IPv6 address represented in binary format and divided into eight 16-bits blocks:<br /> <blockquote> 0010000000000001 0000000000000000 0011001000110100 1101111111100001 0000000001100011 0000000000000000 0000000000000000 1111111011111011</blockquote> Each block is then converted into Hexadecimal and separated by ‘:’ symbol:<br /> <blockquote> 2001:0000:3238:DFE1:0063:0000:0000:FEFB</blockquote> Even after converting into Hexadecimal format, IPv6 address remains long. IPv6 provides some rules to shorten the address. These rules are:<br /> <b>Rule:1</b> Discard leading Zero(es):<br /> In Block 5, 0063, the leading two 0s can be omitted, such as (5th block):<br /> <blockquote> 2001:0000:3238:DFE1:63:0000:0000:FEFB</blockquote> <b>Rule:2</b> If two of more blocks contains consecutive zeroes, omit them all and replace with double colon sign ::, such as (6th and 7th block):<br /> <blockquote> 2001:0000:3238:DFE1:63::FEFB</blockquote> Consecutive blocks of zeroes can be replaced only once by :: so if there are still blocks of zeroes in the address they can be shrink down to single zero, such as (2nd block):<br /> <blockquote> 2001:0:3238:DFE1:63::FEFB</blockquote> <h2> Interface ID</h2> IPv6 has three different type of Unicast Address scheme. The second half of the address (last 64 bits) is always used for Interface ID. MAC address of a system is composed of 48-bits and represented in Hexadecimal. MAC address is considered to be uniquely assigned worldwide. Interface ID takes advantage of this uniqueness of MAC addresses. A host can auto-configure its Interface ID by using IEEE’s Extended Unique Identifier (EUI-64) format. First, a Host divides its own MAC address into two 24-bits halves. Then 16-bit Hex value 0xFFFE is sandwiched into those two halves of MAC address, resulting in 64-bit Interface ID.<br /> <figure> <img caption="EUI-64: Interface ID" src="http://www.tutorialspoint.com/ipv6/images/interface_id.jpg" /> <figcaption align="center">[<i>Image: EUI-64 Interface ID</i>]</figcaption> </figure><h2> Global Unicast Address</h2> This address type is equivalent to IPv4’s public address. Global Unicast addresses in IPv6 are globally identifiable and uniquely addressable. <br /> <figure> <img caption="Global Unicast Address" src="http://www.tutorialspoint.com/ipv6/images/global_unicast_address.jpg" /> <figcaption align="center">[<i>Image: Global Unicast Address</i>]</figcaption> </figure>Global Routing Prefix: The most significant 48-bits are designated as Global Routing Prefix which is assigned to specific Autonomous System. Three most significant bits of Global Routing Prefix is always set to 001.<br /> <h2> Link-Local Address</h2> Auto-configured IPv6 address is known as Link-Local address. This address always starts with FE80. First 16 bits of Link-Local address is always set to 1111 1110 1000 0000 (FE80). Next 48-bits are set to 0, thus:<br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Link-Local Address" src="http://www.tutorialspoint.com/ipv6/images/link_local_address.jpg" /> <figcaption align="center">[<i>Image: Link-Local Address</i>]</figcaption> </figure>Link-Local addresses are used for communication among IPv6 hosts on a link (broadcast segment) only. These addresses are not routable so a Router never forwards these addresses outside the link.<br /> <h2> Unique-Local Address</h2> This type of IPv6 address which is though globally unique, but it should be used in local communication. This address has second half of Interface ID and first half is divided among Prefix, Local Bit, Global ID and Subnet ID.<br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Unique-Local Address" src="http://www.tutorialspoint.com/ipv6/images/unique_local_address.jpg" /> <figcaption align="center">[<i>Image: Unique-Local Address</i>]</figcaption> </figure> Prefix is always set to 1111 110. L bit, which is set to 1 if the address is locally assigned. So far the meaning of L bit to 0 is not defined. Therefore, Unique Local IPv6 address always starts with ‘FD’. <br /> <h3> Scope of IPv6 Unicast Addresses:</h3> <figure> <img caption="IPv6 Unicast Address Scope" src="http://www.tutorialspoint.com/ipv6/images/address_scope.jpg" /> <figcaption align="center">[<i>Image: IPv6 Unicast Address Scope</i>]</figcaption> </figure>The scope of Link-local address is limited to the segment. Unique Local Address are though locally global but are not routed over the Internet, limiting their scope to an organization’s boundary. Global Unicast addresses are globally unique and recognizable. They shall make the essence of Internet v2 addressing.<br /> <h1> Special Addresses</h1> Version 6 has slightly complex structure of IP address than that of IPv4. IPv6 has reserved few addresses and address notations for special purposes. See the table below:<br /> <h2> Special Addresses:</h2> <img caption="Special Address" src="http://www.tutorialspoint.com/ipv6/images/special_address_table.jpg" /> <br /> <ul class="list"> <li>As shown in the table above 0:0:0:0:0:0:0:0/128 address does not specify to anything and is said to be an unspecified address. After simplifying, all 0s are compacted to ::/128.</li> <li>In IPv4, address 0.0.0.0 with netmask 0.0.0.0 represents default route. The same concept is also applie to IPv6, address 0:0:0:0:0:0:0:0 with netmask all 0s represents default route. After applying IPv6 simplying rule this address is compressed to ::/0.</li> <li>Loopback addresses in IPv4 are represented by 127.0.0.1 to 127.255.255.255 series. But in IPv6, only 0:0:0:0:0:0:0:1/128 address represents Loopback address. After simplying loopback address, it can be represented as ::1/128.</li> </ul> <h2> Reserved Multicast Address for Routing Protocols:</h2> <img caption="Multicast Routing Addresses" src="http://www.tutorialspoint.com/ipv6/images/reserved_multicast_routing_address.jpg" /> <br /> <ul class="list"> <li>The above table shows reserved multicast addresses used by interior routing protocol.<br /> </li> <li>All addresses are reserved in similar IPv4 fashion</li> </ul> <h2> Reserved Multicast Address for Routers/Node:</h2> <img caption="Multicast addresses for routers and nodes" src="http://www.tutorialspoint.com/ipv6/images/reserved_multicast_routers_nodes_address.jpg" /> <br /> <ul class="list"> <li>These addresses helps routers and hosts to speak to available routers and hosts on a segment without being configured with an IPv6 address. Hosts use EUI-64 based auto-configuration to self-configure an IPv6 address and then speaks to available hosts/routers on the segment by means of these addresses.</li> </ul> <h1> Headers</h1> The wonder of IPv6 lies in its header. IPv6 address is 4 times larger than IPv4 but the IPv6 header is only 2 times larger than that of IPv4. IPv6 headers have one Fixed Header and zero or more Optional (Extension) Headers. All necessary information which is essential for a router is kept in Fixed Header. Extension Header contains optional information which helps routers to understand how to handle a packet/flow.<br /> <h2> Fixed Header</h2> <figure style="margin: 0px; padding: 0px;"> <img caption="IPv6 Fixed Header" src="http://www.tutorialspoint.com/ipv6/images/IPv6_header.jpg" /> <figcaption align="center">[<i>Image: IPv6 Fixed Header</i>]</figcaption> </figure>IPv6 fixed header is 40 bytes long and contains the following information.<br /> <table class="src"> <tbody> <tr><th style="width: 5%;">S.N.</th><th>Field & Description</th></tr> <tr><td>1</td><td><b>Version</b> (4-bits): This represents the version of Internet Protocol, i.e. 0110.</td></tr> <tr><td>2</td><td><b>Traffic Class</b> (8-bits): These 8 bits are divided into two parts. Most significant 6 bits are used for Type of Service, which tells the Router what services should be provided to this packet. Least significant 2 bits are used for Explicit Congestion Notification (ECN).</td></tr> <tr><td>3</td><td><b>Flow Label</b> (20-bits): This label is used to maintain the sequential flow of the packets belonging to a communication. The source labels the sequence which helps the router to identify that this packet belongs to a specific flow of information. This field helps to avoid re-ordering of data packets. It is designed for streaming/real-time media.</td></tr> <tr><td>4</td><td><b>Payload Length</b> (16-bits): This field is used to tell the routers how much information this packet contains in its payload. Payload is composed of Extension Headers and Upper Layer data. With 16 bits, up to 65535 bytes can be indicated but if Extension Headers contain Hop-by-Hop Extension Header than payload may exceed 65535 bytes and this field is set to 0.</td></tr> <tr><td>5</td><td><b>Next Header</b> (8-bits): This field is used to indicate either the type of Extension Header, or if Extension Header is not present then it indicates the Upper Layer PDU. The values for the type of Upper Layer PDU is same as IPv4’s.</td></tr> <tr><td>6</td><td><b>Hop Limit</b> (8-bits): This field is used to stop packet to loop in the network infinitely. This is same as TTL in IPv4. The value of Hop Limit field is decremented by 1 as it passes a link (router/hop). When the field reaches 0 the packet is discarded.</td></tr> <tr><td>7</td><td><b>Source Address</b> (128-bits): This field indicates the address of originator of the packet.</td></tr> <tr><td>8</td><td><b>Destination Address</b> (128-bits): This field provides the address of intended recipient of the packet.</td></tr> </tbody></table> <h2> Extension Headers</h2> In IPv6, the Fixed Header contains only information which is necessary and avoiding information which is either not required or is rarely used. All such information, is put between the Fixed Header and Upper layer header in the form of Extension Headers. Each Extension Header is identified by a distinct value.<br /> When Extension Headers are used, IPv6 Fixed Header’s Next Header field points to the first Extension Header. If there is one more Extension Header, then first Extension Header’s ‘Next-Header’ field point to the second one, and so on. The last Extension Header’s ‘Next-Header’ field point to Upper Layer Header. Thus all headers from point to the next one in a linked list manner.<br /> If the Next Header field contains value 59, it indicates that there’s no header after this header, not even Upper Layer Header.<br /> The following Extension Headers must be supported as per RFC 2460:<br /> <img caption="Extension Headers" src="http://www.tutorialspoint.com/ipv6/images/extension_headers.jpg" /> <br /> The sequence of Extension Headers should be:<br /> <img caption="Extension Headers Sequence" src="http://www.tutorialspoint.com/ipv6/images/extension_headers_sequence.jpg" /> <br /> These headers:<br /> <ul class="list"> <li>1. Should be processed by First and subsequent destinations.</li> <li>2. Should be processed by Final Destination. </li> </ul> Extension Headers are arranged one after another in a Linked list manner, as depicted in the diagram below:<br /> <figure style="margin: 0px; padding: 0px;"> <img caption="Extension Headers Connection" src="http://www.tutorialspoint.com/ipv6/images/extension_header_sequence.jpg" /> <figcaption align="center">[<i>Image: Extension Headers Connected Format</i>]</figcaption> </figure><h1> Communication</h1> In IPv4, a host which wants to communicate with some other host on the network, needs first to have an IP address acquired either by means of DHCP or by manual configuration. As soon as a host is equipped with some valid IP address, it is now able to speak to any host on the subnet. To communicate on layer-3, a host also must know the IP address of the other host. Communication on a link, is established by means of hardware embedded MAC Addresses. To know the MAC address of host whose IP address is known, a host sends ARP broadcast and in revert the intended host sends back its MAC address.<br /> In IPv6, there’s no broadcast mechanism. It is not a must for an IPv6 enabled host to obtain IP address from DHCP or manually configured, but it can auto-configure its own IP. Then, how would a host communicates with others on IPv6 enabled network?<br /> ARP has been replaced by ICMPv6 Neighbor Discovery Protocol.<br /> <h2> Neighbor Discovery Protocol</h2> A host in IPv6 network is capable of auto-configuring itself with a unique link-local address. As soon as it is equipped with an IPv6 address, it joins a number of multicast groups. All communications related to that segment happens on those multicast addresses only. A host goes through a series of states in IPv6:<br /> <ul class="list"> <li><b>Neighbor Solicitation</b>: After configuring all IPv6’s either manually, or by DHCP Server or by auto-configuration, the host sends a Neighbor Solicitation message out to FF02::1/16 multicast address for all its IPv6 addresses in order to know that no one else occupies same addresses.</li> <li><b>DAD (Duplicate Address Detection)</b>: When the host does not listen from anything from the segment regarding its Neighbor Solicitation message, it assumes that no duplicate address exists on the segment.</li> <li><b>Neighbor Advertisement</b>: After assigning the addresses to its interfaces and making them up and running, the host once again sends out a Neighbor Advertisement message telling all other hosts on the segment, that it has assigned those IPv6 addresses to its interfaces.</li> </ul> Once a host is done with the configuration of its IPv6 addresses, it does the following things:<br /> <ul class="list"> <li><b>Router Solicitation</b>: A host sends a Router Solicitation multicast packet (FF02::2/16) out on its segment to know the presence of any router on this segment. This helps the host to configure the router as its default gateway. If its default gateway router goes down, the host can shift to a new router and makes it the default gateway.</li> <li><b>Router Advertisement</b>: When a router receives a Router Solicitation message, it responses back to the host advertising its presence on that link.</li> <li><b>Redirect</b>: This may be the situation where a Router receives a Router Solicitation request but it knows that it is not the best gateway for the host. In this situation, the router sends back a Redirect message telling the host that there is a better ‘next-hop’ router available. Next-hop is where the host will send its data destined to a host which does not belong to the same segment.</li> </ul> <h1> Subnetting</h1> In IPv4, addresses were created in classes. Classful IPv4 addresses clearly defines the bits used for network prefixes and the bits used for hosts on that network. To subnet in IPv4 we play with the default classful netmask which allows us to borrow hosts bit to be used as subnet bits. This results in multiple subnets but less hosts per subnet. That is, when we borrow host bit to create a subnet that costs us in lesser bit to be used for host addresses.<br /> IPv6 addresses uses 128 bits to represent an address which includes bits to be used for subnetting. Second half of the address (least significant 64 bits) is always used for Hosts only. Therefore, there is no compromise if we subnet the network.<br /> <figure> <img caption="IPv6 Subnetting" src="http://www.tutorialspoint.com/ipv6/images/subnetting.jpg" /> <figcaption align="center">[<i>Image: IPv6 Subnetting</i>]</figcaption> </figure>16 Bits of subnet is equivalent to IPv4’s Class B Network. Using these subnet bits an organization can have more 65 thousands of subnets which is by far, more than enough.<br /> Thus routing prefix is /64 and host portion is 64 bits. We though, can further subnet the network beyond 16 bits of Subnet ID, borrowing hosts bit but it is recommended that 64 bits should always be used for hosts addresses because auto-configuration requires 64 bits.<br /> IPv6 subnetting works on the same concept as Variable Length Subnet Masking in IPv4.<br /> /48 prefix can be allocated to an organization providing it the benefit of having up to /64 subnet prefixes, which is 65535 sub-networks, each having 264 hosts. A /64 prefix can be assigned to a point-to-point connection where there are only two hosts (or IPv6 enabled devices) on a link.<br /> <h1> IPv4 to IPv6</h1> One problem in transition from IPv4 to IPv6 completely is that IPv6 is not backward compatible. This results in a situation where either a site is on IPv6 or it is not. Unlike an implementation of new technology where the newer one is backward compatible so the older system can still work with the newer without any additional changes.<br /> To overcome this short-coming, there exist few technologies which can be used in slow and smooth transition from IPv4 to IPv6:<br /> <h2> Dual Stack Routers</h2> A router can be installed with both IPv4 and IPv6 addresses configured on its interfaces pointing to the network of relevant IP scheme.<br /> <figure> <img caption="Dual Stack Router" src="http://www.tutorialspoint.com/ipv6/images/dual_stack_router.jpg" /> <figcaption align="center">[<i>Image: Dual Stack Router</i>]</figcaption> </figure>In above diagram, a Server which is having IPv4 as well as IPv6 address configured for it now can speak with all hosts on IPv4 network and IPv6 network with help of Dual Stack Router. Dual Stack Router, can communicate with both networks and provides a medium for hosts to access Server without changing their respective IP version.<br /> <h2> Tunneling</h2> In a scenario where different IP versions exist on intermediate path or transit network, tunneling provides a better solution where user’s data can pass through a non-supported IP version.<br /> <figure> <img caption="Tunneling" src="http://www.tutorialspoint.com/ipv6/images/tunneling.jpg" /> <figcaption align="center">[<i>Image: Tunneling</i>]</figcaption> </figure>The above diagram depicts how two remote IPv4 networks can communicate via Tunnel, where the transit network was on IPv6. Vice versa is also possible where transit network is on IPv6 and remote sites which intends to communicate, are on IPv4.<br /> <h2> NAT Protocol Translation</h2> This is another important method of transition to IPv6 by means of a NAT-PT (Network Address Translation – Protocol Translation) enabled device. With help of NAT-PT device, actual conversion happens between IPv4 and IPv6 packets and vice versa. See the diagram below:<br /> <figure> <img caption="NAT-PT" src="http://www.tutorialspoint.com/ipv6/images/nat.jpg" /> <figcaption align="center">[<i>Image: NAT - Protocol Translation</i>]</figcaption> </figure>A host with IPv4 address sends a request to IPv6 enabled Server on Internet which does not understand IPv4 address. In this scenario, NAT-PT device can help them communicate. When IPv4 host sends a request packet to IPv6 Server, NAT-PT device/router, strips down the IPv4 packet, removes IPv4 header and adds IPv6 header and passes it through the Internet. When a response from IPv6 Server comes for IPv4 host, the router does vice versa.<br /> <h1> Mobility</h1> When a host is connected to one link or network, it acquires an IP address and all communication happens using that IP address on that link. As soon as, the same host changes its physical location, that is, moves into some different area / subnet / network / link, its IP address changes accordingly and all communication happening on the host using old IP address, goes down.<br /> IPv6 mobility provides a mechanism which equips a host with an ability to roam around among different links without losing any communication/connection and its IP address.<br /> Multiple entities are involved in this technology:<br /> <ul class="list"> <li><b>Mobile Node</b>: The device which needs IPv6 mobility. </li> <li><b>Home Link</b>: This link is configured with the home subnet prefix and this is where the Mobile IPv6 device gets its Home Address.</li> <li><b>Home Address</b>: This is the address which Mobile Node acquires from Home Link. This is permanent address of Mobile Node. If the Mobile Node remains in the same Home Link, the communication among various entities happens as usual.</li> <li><b>Home Agent</b>: This is a router which acts as registrar for Mobile Nodes. Home Agent is connected to Home Link and maintains information about all Mobile Nodes, their Home Addresses and their present IP addresses.</li> <li><b>Foreign Link</b>: Any other Link which is not Mobile Node’s Home Link.</li> <li><b>Care-of Address</b>: When a Mobile Node attaches to a Foreign Link, it acquires a new IP address of that Foreign Link’s subnet. Home Agent maintains the information of both Home Address and Care-of Address. Multiple Care-of addresses can be assigned to Mobile Node, but at any instance only one Care-of Address has binding with Home Address.</li> <li><b>Correspondent Node</b>: Any IPv6 enable device which intends to have communication with Mobile Node.</li> </ul> <h2> Mobility Operation</h2> When Mobile Node stays in its Home Link, all communications happen on its Home Address. As shown below:<br /> <figure> <img caption="Mobile Node in Home Link" src="http://www.tutorialspoint.com/ipv6/images/MN_in_HL.jpg" /> <figcaption align="center">[<i>Image: Mobile Node connected to Home Link</i>]</figcaption> </figure>When Mobile Node leaves its Home Link and is connected to some Foreign Link, the Mobility feature of IPv6 comes into play. After connecting to Foreign Link, Mobile Node acquires an IPv6 address from Foreign Link. This address is called Care-of Address. Mobile Node sends binding request to its Home Agent with the new Care-of Address. Home Agent binds Mobile Node’s Home Address with Care-of Address, establishing a Tunnel between both.<br /> Whenever a Correspondent Node tries to establish connection with Mobile Node (on its Home Address), the Home Agent intercepts the packet and forwards to Mobile Node’s Care-of Address over the Tunnel which was already established.<br /> <figure> <img caption="Mobile Node in Foreign Link" src="http://www.tutorialspoint.com/ipv6/images/MN_in_FL.jpg" /> <figcaption align="center">[<i>Image: Mobile Node connected to Foreign Link</i>]</figcaption> </figure><h2> Route Optimization</h2> When a Correspondent Node initiate communication by sending packets to Mobile Node on Home Address, these packets are tunneled to Mobile Node by Home Agent. In Route Optimization mode, when the Mobile Node receives packet from Correspondent Node, it does not forward replies to Home Agent. Rather it sends its packet directly to Correspondent Node using Home Address as Source Address. This mode is optional and not used by default.<br /> <h1> Routing</h1> Routing concepts remain same in case of IPv6 but almost all routing protocol have been redefined accordingly. We have seen in Communication in IPv6 segment, how a host speaks to its gateway. Routing is a process to forward routable data choosing best route among several available routes or path to the destination. A router is a device which forwards data which is not explicitly destined to it.<br /> There exists two forms of routing protocols<br /> <ul class="list"> <li><b>Distance Vector Routing Protocol</b>: A router running distance vector protocol advertises its connected routes and learns new routes from its neighbors. The routing cost to reach a destination is calculated by means of hops between the source and destination. A Router generally relies on its neighbor for best path selection, also known as “routing-by-rumors”. RIP and BGP are Distance Vector Protocols.</li> <li><b>Link-State Routing Protocol</b>: This protocol acknowledges the state of a Link and advertises to its neighbors. Information about new links is learnt from peer routers. After all the routing information has been converged, Link-State Routing Protocol uses its own algorithm to calculate best path to all available links. OSPF and IS-IS are link state routing protocols and both uses Djikstra’s Shortest Path First algorithm.</li> </ul> Routing protocols can be divided in two categories:<br /> <ul class="list"> <li><b>Interior Routing Protocol</b>: Protocols in this categories are used within an Autonomous System or organization to distribute routes among all routers inside its boundary. Examples: RIP, OSPF.</li> <li><b>Exterior Routing Protocol</b>: Whereas an Exterior Routing Protocol distributes routing information between two different Autonomous Systems or organization. Examples: BGP.</li> </ul> <h2> Routing protocols</h2> <ul class="list"> <li><b>RIPng</b><br /> RIPng stands for Routing Information Protocol Next Generation. This is an Interior Routing Protocol and is a Distance Vector Protocol. RIPng has been upgraded to support IPv6.<br /> </li> <li><b>OSPFv3</b></li> Open Shortest Path First version 3 is an Interior Routing Protocol which is modified to support IPv6. This is a Link-State Protocol and uses Djikrasta’s Shortest Path First algorithm to calculate best path to all destinations.<br /> <li><b>BGPv4</b><br /> BGP stands for Border Gateway Protocol. It is the only open standard Exterior Gateway Protocol available. BGP is a Distance Vector protocol which takes Autonomous System as calculation metric, instead of number of routers as Hop. BGPv4 is an upgrade of BGP to support IPv6 routing.</li> </ul> <h2> Protocols changed to support IPv6:</h2> <ul class="list"> <li><b>ICMPv6</b>: Internet Control Message Protocol version 6 is an upgraded implementation of ICMP to accommodate IPv6 requirements. This protocol is used for diagnostic functions, error and information message, statistical purposes. ICMPv6’s Neighbor Discovery Protocol replaces ARP and helps discover neighbor and routers on the link.</li> <li><b>DHCPv6</b>: Dynamic Host Configuration Protocol version 6 is an implementation of DHCP. Though IPv6 enabled hosts do not require any DHCPv6 Server to acquire IP address as they can be auto-configured. Neither do they need DHCPv6 to locate DNS server because DNS can be discovered and configured via ICMPv6 Neighbor Discovery Protocol. Yet DHCPv6 Server can be used to provide these information. </li> <li><b>DNS</b>: There has been no new version of DNS but it is now equipped with extensions to provide support for querying IPv6 addresses. A new AAAA (quad-A) record has been added to reply IPv6 query messages. Now DNS can reply with both IP versions (4 & 6) without any change in query format.</li> </ul> <h1> Summary</h1> IPv4 since 1982, has been an undisputed leader of Internet. With IPv4’s address space exhaustion IPv6 is now taking over the control of Internet, which is called Internet2.<br /> IPv4 is widely deployed and migration to IPv6 would not be easy. So far IPv6 could penetrate IPv4’s address space by less than 1%. <br /> The world has celebrated ‘World IPv6 Day’ on June 08, 2011 with a purpose to test IPv6 address over Internet in full. On June 06, 2012 the Internet community officially launched IPv6. This day all ISPs who were offering IPv6 were to enable it on public domain and were to keep it enable. All the device manufacturer also participated to offer IPv6 by-default enabled on devices.<br /> This was a step towards encouraging Internet community to migrate to IPv6.<br /> Organizations are provided plenty of ways to migrate from IPv4 to IPv6. Also organization, willing to test IPv6 before migrating completely can run both IPv4 and IPv6 simultaneously. Networks of different IP versions can communicate and user data can be tunneled to walk to the other side.<br /> <h2> Future of IPv6</h2> IPv6 enabled Internet version 2 will replace todays IPv4 enabled Internet. When Internet was launched with IPv4, developed countries like US and Europe took the larger space of IPv4 for deployment of Internet in their respective countries keeping future need in mind. But Internet exploded everywhere reaching and connecting every country of the world increasing the requirement of IPv4 address space. As a result, till this day US and Europe have many IPv4 address space left with them and countries like India and China are bound to address their IP space requirement by means of deployment of IPv6.<br /> Most of the IPv6 deployment is being done outside US, Europe. India and China are moving forward to change their entire space to IPv6. China has announced a five year deployment plan named China Next Generation Internet.<br /> After June 06, 2012 all major ISPs were shifted to IPv6 and rest of them are still moving.<br /> <br /> IPv6 provides ample of address space and is designed to expand today’s Internet services. Feature-rich IPv6 enabled Internet version 2 may deliver more than expected.<br /> <br /> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/ipv6-quick-guide.html">http://ipv4-ipv6.blogspot.com/2014/07/ipv6-quick-guide.html</a></span>

IPv6 Quick Guide

Tukiyooo 1 01:11

Overview Internet Protocol version 6, is a new addressing protocol designed to incorporate whole sort of requirement of future internet known to us as Internet version 2. This protocol as its predecessor IPv4, works on Network Layer (Layer-3). … Read more »

Read more »

IPv6 Features

The successor of IPv4 is not designed to be backward compatible. Trying to keep the basic functionalities of IP addressing, IPv6 is redesigned entirely. It offers the following features:<br /> <ul class="list"> <li><b> Larger Address Space: </b><br /> In contrast to IPv4, IPv6 uses 4 times more bits to address a device on the Internet. This much of extra bits can provide approximately 3.4×1038 different combinations of addresses. This address can accumulate the aggressive requirement of address allotment for almost everything in this world. According to an estimate, 1564 addresses can be allocated to every square meter of this earth. </li> <li><b>Simplified Header:</b><br /> IPv6’s header has been simplified by moving all unnecessary information and options (which are present in IPv4 header) to the end of the IPv6 header. IPv6 header is only twice as bigger than IPv4 providing the fact the IPv6 address is four times longer. </li> <li><b>End-to-end Connectivity:</b><br /> Every system now has unique IP address and can traverse through the internet without using NAT or other translating components. After IPv6 is fully implemented, every host can directly reach other host on the Internet, with some limitations involved like Firewall, Organization’s policies, etc.</li> <li><b>Auto-configuration:</b><br /> IPv6 supports both stateful and stateless auto configuration mode of its host devices. This way absence of a DHCP server does not put halt on inter segment communication. </li> <li><b>Faster Forwarding/Routing:</b><br /> Simplified header puts all unnecessary information at the end of the header. All information in first part of the header are adequate for a Router to take routing decision thus making routing decision as quickly as looking at the mandatory header.</li> <li><b>IPSec:</b><br /> Initially it was decided for IPv6 to must have IPSec security, making it more secure than IPv4. This feature has now been made optional.</li> <li><b>No Broadcast:</b><br /> Though Ethernet/Token Ring are considered as broadcast network because they support Broadcasting, IPv6 does not have any Broadcast support anymore left with it. It uses multicast to communicate with multiple hosts. </li> <li><b>Anycast Support:</b><br /> This is another characteristic of IPv6. IPv6 has introduced Anycast mode of packet routing. In this mode, multiple interfaces over the Internet are assigned same Anycast IP address. Routers, while routing, sends the packet to the nearest destination.</li> <li><b>Mobility:</b><br /> IPv6 was designed keeping mobility feature in mind. This feature enables hosts (such as mobile phone) to roam around in different geographical area and remain connected with same IP address. IPv6 mobility feature takes advantage of auto IP configuration and Extension headers.</li> <li><b>Enhanced Priority support:</b><br /> Where IPv4 used 6 bits DSCP (Differential Service Code Point) and 2 bits ECN (Explicit Congestion Notification) to provide Quality of Service but it could only be used if the end-to-end devices support it, that is, the source and destination device and underlying network must support it. <br /> In IPv6, Traffic class and Flow label are used to tell underlying routers how to efficiently process the packet and route it.</li> <li><b>Smooth Transition:</b><br /> Large IP address scheme in IPv6 enables to allocate devices with globally unique IP addresses. This assures that mechanism to save IP addresses such as NAT is not required. So devices can send/receive data between each other, for example VoIP and/or any streaming media can be used much efficiently.<br /> Other fact is, the header is less loaded so routers can make forwarding decision and forward them as quickly as they arrive.</li> <li><b>Extensibility:</b><br /> One of the major advantage of IPv6 header is that it is extensible to add more information in the option part. IPv4 provides only 40-bytes for options whereas options in IPv6 can be as much as the size of IPv6 packet itself</li> </ul> <div> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;"><a href="http://ipv4-ipv6.blogspot.com/2014/07/the-successor-of-ipv4-is-not-designed.html">http://ipv4-ipv6.blogspot.com/2014/07/the-successor-of-ipv4-is-not-designed.html</a></span></div>

IPv6 Features

Tukiyooo 0 01:08

The successor of IPv4 is not designed to be backward compatible. Trying to keep the basic functionalities of IP addressing, IPv6 is redesigned entirely. It offers the following features: Larger Address Space: In contrast to IPv4, IPv6 uses 4 ti… Read more »

Read more »

IPv6 Overview

<a href="http://ipv4-ipv6.blogspot.com/" target="_blank">Internet Protocol version 6</a>, is a new addressing protocol designed to incorporate whole sort of requirement of future internet known to us as Internet version 2. This protocol as its predecessor IPv4, works on Network Layer (Layer-3). Along with its offering of enormous amount of logical address space, this protocol has ample of features which addresses today’s shortcoming of IPv4.<br /> <h2> Why new IP version?</h2> So far, IPv4 has proven itself as a robust routable addressing protocol and has served human being for decades on its best-effort-delivery mechanism. It was designed in early 80’s and did not get any major change afterward. At the time of its birth, Internet was limited only to a few Universities for their research and to Department of Defense. IPv4 is 32 bits long which offers around 4,294,967,296 (2³²) addresses. This address space was considered more than enough that time. Given below are major points which played key role in birth of IPv6:<br /> <ul class="list"> <li>Internet has grown exponentially and the address space allowed by IPv4 is saturating. There is a requirement of protocol which can satisfy the need of future Internet addresses which are expected to grow in an unexpected manner.</li> <li>Using features such as NAT, has made the Internet discontiguous i.e. one part which belongs to intranet, primarily uses private IP addresses; which has to go through number of mechanism to reach the other part, the Internet, which is on public IP addresses.</li> <li>IPv4 on its own does not provide any security feature which is vulnerable as data on Internet, which is a public domain, is never safe. Data has to be encrypted with some other security application before being sent on Internet.</li> <li>Data prioritization in IPv4 is not up to date. Though IPv4 has few bits reserved for Type of Service or Quality of Service, but they do not provide much functionality.</li> <li>IPv4 enabled clients can be configured manually or they need some address configuration mechanism. There exists no technique which can configure a device to have globally unique IP address.</li> </ul> <h2> Why not IPv5?</h2> Till date, Internet Protocol has been recognized has IPv4 only. Version 0 to 3 were used while the protocol was itself under development and experimental process. So, we can assume lots of background activities remain active before putting a protocol into production. Similarly, protocol version 5 was used while experimenting with stream protocol for internet. It is known to us as Internet Stream Protocol which used Internet Protocol number 5 to encapsulate its datagram. Though it was never brought into public use, but it was already used.<br /> Here is a table of IP version and their use:<br /> <img alt="IPv6 Version Table" src="http://www.tutorialspoint.com/ipv6/images/ip_version_table.jpg" /> <br /> <h2> Brief History</h2> After IPv4’s development in early 80s, the available IPv4 address pool begun to shrink rapidly as the demand of addresses exponentially increased with Internet. Taking pre-cognizance of situation that might arise IETF, in 1994, initiated the development of an addressing protocol to replace IPv4. The progress of IPv6 can be tracked by means of RFC published:<br /> <ul class="list"> <li>1998 – RFC 2460 – Basic Protocol</li> <li>2003 – RFC 2553 – Basic Socket API</li> <li>2003 – RFC 3315 – DHCPv6</li> <li>2004 – RFC 3775 – Mobile IPv6</li> <li>2004 – RFC 3697 – Flow Label Specification</li> <li>2006 – RFC 4291 – Address architecture (revision)</li> <li>2006 – RFC 4294 – Node requirement</li> </ul> <br /> June 06, 2012 some of Internet giants chose to put their Servers on IPv6. Presently they are using Dual Stack mechanism to implement IPv6 parallel with IPv4.<br /> <span style="background-color: #edf4ff; color: #888888; font-family: Arial, Helvetica, sans-serif; font-size: 13px;">http://ipv4-ipv6.blogspot.com/2014/07/ipv6-overview.html</span>

IPv6 Overview

Tukiyooo 0 01:06

Internet Protocol version 6, is a new addressing protocol designed to incorporate whole sort of requirement of future internet known to us as Internet version 2. This protocol as its predecessor IPv4, works on Network Layer (Layer-3). Along with… Read more »

Read more »

What is IPv4 and IPv6 ?

<div class="_5pbx userContent" data-ft="{"tn":"K"}"> <a href="http://ipv4-ipv6.blogspot.com/" target="_blank">What is IPv4 and IPv6. ?</a><br /> Are you confused between IPv4 and IPv6 .Here I have listed the Differences between them. <br /> IPv4 :-<br /> 1) All the addresses of IPv4 are 32 bit length<br /> 2)The support of IPsec is only Optional<br /> 3)The Senders and Forwarding Routers will do the Fragmentation<br /> 4) Broadcasts Messages are available too<br /> 5)Static of IP addresses or Dynamic configuration is required to Configure IP address<br /> 6)No Packet Flow identification<br /> 7) Internet group Management Protocol ( IGMP ) is used for the Multicast Group Membership.<br /> IPv6:-<br /> 1) All the addresses of IPv4 are 128 bit length<br /> 2) Inbuilt IPsec Support<br /> 3) Only Sender will do the Fragmentation<br /> 4)) Broadcasts Messages are not available.Instead a Link local scope all nodes multi cast address is used for Broadcast<br /> 5)Auto configuration of Addresses is Available<br /> 6)Packet Flow identification is available within the IPv6 header Using the Flow Label Field<br /> 7) IGMP is replaced with the Neighbour Discovery Protocol.<br /> Author: <a class="profileLink" href="https://www.facebook.com/1337vickz" rel="nofollow" target="_blank">Vicky singh</a></div>

What is IPv4 and IPv6 ?

Tukiyooo 0 01:02

What is IPv4 and IPv6. ? Are you confused between IPv4 and IPv6 .Here I have listed the Differences between them. IPv4 :- 1) All the addresses of IPv4 are 32 bit length 2)The support of IPsec is only Optional 3)The Senders and Forwarding Routers… Read more »

Read more »

World IPv6 day (Test Flight)

<div class="_5rgo"> <div class="msg _599f _5tfq"> <div> Today is the World IPv6 day or "Test Flight" day and the goal of the Test Flight Day is to motivate organizations across the industry – Internet service providers, hardware makers, operating system vendors and web companies – to prepare their services for IPv6 to ensure a successful transition as IPv4 addresses run out.<br /> <br /> Including Google, Facebook, Yahoo!, Akamai and Limelight Networks will offer their contents over IPv6 for 24 hours.<br /> <br /> You can check your IPv6 through the <a href="http://lm.facebook.com/l.php?u=http%3A%2F%2Ftest-ipv6.com%2F&h=dAQEBlw_3&s=1" rel="nofollow" target="_blank">http://test-ipv6.com/</a>.<br /> <br /> Google has announced that if any problem occured to visit Google then they recommend to use ipv4.google.com rather using <a href="http://lm.facebook.com/l.php?u=http%3A%2F%2Fwww.google.com%2F&h=TAQEEBq0U&s=1" rel="nofollow" target="_blank">www.google.com</a> on june 8.<br /> <br /> Although you havent IPv6 , its not problem because they are not going to completly cwitch to IPv6 , They going to use both IP versions for the users on 8 th of june.<br /> <br /> you can read  more about google announcement from <a href="http://lm.facebook.com/l.php?u=http%3A%2F%2Fipv4.google.com%2Fsupport%2Fwebsearch%2Fbin%2Fanswer.py%3Fanswer%3D1299266%26topic%3D8995%26hl%3Den&h=LAQEDhFFy&s=1" rel="nofollow" target="_blank">ipv4.google.com/support/websearch/bin/answer.py?answer=1299266&topic=8995&hl=en</a></div> </div> </div>

World IPv6 day (Test Flight)

Tukiyooo 0 10:27

Today is the World IPv6 day or "Test Flight" day and the goal of the Test Flight Day is to motivate organizations across the industry – Internet service providers, hardware makers, operating system vendors and web companies – to prepare their se… Read more »

Read more »

How to add IPv6 over IPv4 support to your network behind a NAT router

<pre>Firewall+IPv6 Tunnel mini-HOWTO Hernán Freschi <hjf(at)hjf.com.ar> version 0.1, 2002-11-27 How to add IPv6 over IPv4 support to your network behind a NAT router. ---------------------------------------------------------------------- Table of Contents 1. Introduction 1.1 Copyright 1.2 Disclaimer 1.3 Credits 1.4 Changelog 2. What's IPv6? What can it do for me? 3. How do I connect to the 6bone? 4. What should I allow through the firewall? 5. Configuring the IPv6 machines/routers 5.1. Linux 5.2. Windows 5.2.1 IPv6 stand-alone machine 5.2.2 IPv6 network 5.2.2.1 The Router 5.2.2.2 The clients 6. Examples 6.1 Windows PC using IPv6, behind iptables NAT/MASQ, with a tunnel from HE. 6.2 Multiple Windows PCs using IPv6, behind iptables NAT/MASQ, with a tunnel from BTExact. ---------------------------------------------------------------------- 1. Introduction 1.1 Copyright This document is Copyright 2002 by Hernán Freschi. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license can be found at www.gnu.org. 1.2 Disclaimer Use the information in this document at your own risk. I disavow any potential liability for the contents of this document. Use of the concepts, examples, and/or other content of this document is entirely at your own risk. All copyrights are owned by their owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark. Naming of particular products or brands should not be seen as endorsements. You are strongly recommended to take a backup of your system before major installation and backups at regular intervals. 1.3 Credits Hernán Freschi <hjf(at)hjf.com.ar> Microsoft, Windows, 2000, XP, SP1, .NET Server 2003 are all trademarks of Microsoft Corp. Any comments or suggestions can be mailed to my mail address on: hjf(at)hjf.com.ar This document is still in beta phase, so errors and omissions may be present. 1.4 Changelog 0.1 Initial Release. Getting Started 2. What's IPv6? What can it do for me? Sorry, that is beyond the scope of this document. This aims to make a iptables firewall to allow incoming traffic from an IPv6 tunnel. 3. How do I connect to the 6bone? Through a tunnel broker!. Get your account (for free) at: www.tunnelbroker.net (USA) tb.ipv6.btexact.com (UK) tb.ngnet.it (Italy?) You could also use www.freenet6.net, but they use proprietary software, which doesn't run inside a network. But it's easier to implement and even assigns /48 subnets. 4. What should I allow through the firewall? Everything that comes from the tunnel address, except ICMP (what for? let the linux box answer, so the packets dont get in the network). The rules I use are this: iptables -A FORWARD -s <tunnel address> -p ! ICMP -i eth0 -j ACCEPT iptables -t nat -A PREROUTING -i eth0 -j DNAT --to <internal router address> And that's it. The outgoing packets don't need special treatment. Note: This, of course, assumes that your Linux firewall doesn't handle the IPv6 packets. It's designed to run on tiny distros like FloppyFW (www.zelow.no/floppyfw) or LRP (www.lrp.org). With this, the firewall doesn't need support for IPv6. These packets are handled in an internal, more powerful (ie: with a hard disk) computer. 5. Configuring the IPv6 machines/routers 5.1 Linux I don't have a linux box to experiment, you can either a) Donate a hard disk, so I can install linux again or b) Write this section for me :) 5.2 Windows (2000/XP/XP-SP1/.NET Server 2003 ONLY! Win9x is UNSUPPORTED). First of all, you have to install IPv6 support: C:\> ipv6 install Installing... Success. 5.2.1 IPv6 stand-alone machine: Use your brokers script! If they didn't provide one, use these: ipv6.exe rtu ::/0 2/::<tunnel address> ipv6.exe adu 2/<your ipv6 address> The 2/ is the Interface Index. It's usually 2, but it may vary. If in doubt, type ipv6 if and look for a line like this: Interface 2: Automatic tunnel pseudo-interface The number, obviously, is the one you are looking for. 5.2.2 IPv6 network (Note: this applies only to the external network. If you need help setting up the IPv6 lan, read www.microsoft.com/ipv6) 5.2.2.1 The Router Use your brokers script! If they didn't provide one, use these: ipv6.exe rtu ::/0 2/::<tunnel address> ipv6.exe adu 2/<your ipv6 address> ipv6.exe rtu <your ipv6 subnet>/<your ipv6 netmask> 4 pub life 86400 ipv6.exe ifc 2 forw ipv6.exe ifc 3 forw ipv6.exe ifc 4 forw adv 2, 3, 4 are the interface indices. They may vary. To find out, type ipv6 if 5.2.2.2 The clients You don't need to do nothing, they are auto configured. 6. Examples: 6.1 Windows PC using IPv6, behind iptables NAT/MASQ, with a tunnel from HE. Equipment required: 1 Box capable of running iptables (kernel = 2.4.x) 1 Box running Microsoft® Windows 2000, Windows XP (SP1), Windows .NET Server 2003. Tunnel: 1 /127 Allocation from Hurricane Electric +---+ +---+ \/\/\/\/\/ +------+ /\/\/\/\/\ |WIN|------------|FFW|-----------/INTERNET\---------|TUNNEL|----------\ 6bone / +---+ +---+ \/\/\/\/\/ +------+ /\/\/\/\/\ 10.42.42.100<->10.42.42.1 <-> 209.13.122.2 <-> ipv6.he.net <-> 2001:470:1F00:FFFF::xxxx Configuration: On the Linux box type: iptables -A FORWARD -s 64.71.128.82 -p ! ICMP -i eth0 -j ACCEPT iptables -t nat -A PREROUTING -s 64.71.128.82 -i eth0 -j DNAT --to 10.42.42.100 On the MS box type: ipv6 rtu ::/0 2/::64.71.128.82 pub ipv6 adu 2/2001:470:1F00:FFFF::xxxx Congratulations. You are set. Now try pinging to 6bone.net, for example. 6.2 Multiple Windows PCs using IPv6, behind iptables NAT/MASQ, with a tunnel from BTExact. Equipment required: 1 Box capable of running iptables (kernel = 2.4.x) n Boxes running Microsoft® Windows 2000, Windows XP (SP1), Windows .NET Server 2003. Tunnel: 1 /64 Allocation from Hurricane Electric +---+ +---+ +---+ |WIN| |WIN| |WIN| +---+ +---+ +---+ +-----+-----+ +---+ +---+ \/\/\/\/\/ +------+ /\/\/\/\/\ --|WRT|------------|FFW|-----------/INTERNET\---------|TUNNEL|----------\ 6bone / +---+ +---+ \/\/\/\/\/ +------+ /\/\/\/\/\ 10.42.42.100<->10.42.42.1 <-> 209.13.122.2 <-> 193.113.58.80 <-> 2001:618:400::xxxx:xxxx Configuration: On the Linux box type: iptables -A FORWARD -s 64.71.128.82 -p ! ICMP -i eth0 -j ACCEPT iptables -t nat -A PREROUTING -s 64.71.128.82 -i eth0 -j DNAT --to 10.42.42.100 On the MS router type: ipv6.exe rtu ::/0 2/::193.113.58.80 ipv6.exe adu 2/2001:618:400::xxxx:xxxx ipv6.exe rtu 2001:618:400:xxxx::/64 4 pub life 86400 ipv6.exe ifc 2 forw ipv6.exe ifc 3 forw ipv6.exe ifc 4 forw adv On the other machines type: Nothing, they are auto configured. If they dont work, try: ipv6 reset If that doesn't work, check for a default route (::/0). ipv6 rt If there isn't one, try adding one: ipv6 rtu ::/0 n/(your routers ipv6 address) (where n is the interface index of the ethernet board connected to the network, usually 4). If it works, but the next time you reboot, it does not auto configure, then maybe you are not publishing the default route in the router. Congratulations. You are set. Now try pinging to 6bone.net, for example. </pre>

How to add IPv6 over IPv4 support to your network behind a NAT router

Tukiyooo 0 19:12

Firewall+IPv6 Tunnel mini-HOWTO Hernán Freschi version 0.1, 2002-11-27 How to add IPv6 over IPv4 support to your network behind a NAT router. ---------------------------------------------------------------------- Table of Contents 1. Introduction … Read more »

Read more »

IPv6 multicast address assignment with DHCPv6

<pre>Network Working Group J. Durand Internet-Draft GIP RENATER Expires: August 19, 2005 February 18, 2005 IPv6 multicast address assignment with DHCPv6 draft-jdurand-assign-addr-ipv6-multicast-dhcpv6-01 Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 19, 2005. Copyright Notice Copyright (C) The Internet Society (2005). All Rights Reserved. Abstract This document proposes a simple solution to solve IPv6 multicast address assignment problem using the DHCPv6 protocol. Durand Expires August 19, 2005 [Page 1] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 IPv6 multicast deployment status . . . . . . . . . . . . . 3 1.2 Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 SSM: no solution needed . . . . . . . . . . . . . . . . . 3 1.4 Session announcement considerations . . . . . . . . . . . 4 2. State of the art for address assignment . . . . . . . . . . . 4 3. Assignment with DHCPv6 . . . . . . . . . . . . . . . . . . . . 4 3.1 New DHCPv6 options . . . . . . . . . . . . . . . . . . . . 4 3.1.1 IA_MA option for IPv6 Multicast Addresses . . . . . . 4 3.1.2 Scope Option for IPv6 multicast address . . . . . . . 6 3.2 Address timers . . . . . . . . . . . . . . . . . . . . . . 6 3.3 Assignment of a multicast prefix . . . . . . . . . . . . . 7 3.4 Client and server behavior . . . . . . . . . . . . . . . . 7 4. Group-ID consideration . . . . . . . . . . . . . . . . . . . . 8 5. Deployment scenarios - Case studies . . . . . . . . . . . . . 8 5.1 Scenario 1: Site deployment . . . . . . . . . . . . . . . 8 5.2 Scenario 2: Campus deployment . . . . . . . . . . . . . . 9 5.3 Scenario 3: ISP deployment . . . . . . . . . . . . . . . . 9 6. Security considerations . . . . . . . . . . . . . . . . . . . 9 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 10 8. Discussions . . . . . . . . . . . . . . . . . . . . . . . . . 10 9. Changes from -00 . . . . . . . . . . . . . . . . . . . . . . . 10 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 10.1 Normative references . . . . . . . . . . . . . . . . . . . . 10 10.2 Informative references . . . . . . . . . . . . . . . . . . . 11 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 13 Durand Expires August 19, 2005 [Page 2] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 1. Introduction Embedded-RP [11] is the only available solution for IPv6 interdomain ASM. Embedded-RP requires an IPv6 multicast address assignment mechanism, as multicast addresses mapping to the RP cannot be guessed and manually built by users. This is depicted in section 2.1.2 of the IETF working group document draft-ietf-mboned-addrarch [13]. This document proposes a simple solution to assign IPv6 multicast addresses or prefixes using the DHCPv6 protocol [8]. 1.1 IPv6 multicast deployment status The document draft-jdurand-ipv6-multicast-ra [14] recalls the following: "The deployment of IPv6 multicast is expanding. Some networks have already put the service in production. Some gateways have been deployed, making it possible to have interoperability between IPv4 and IPv6 multicast. Some sites have even stopped IPv4 multicast, due to its complexity (due to NAT and MSDP for example) and only rely on IPv6 multicast, using the deployed gateways for interoperability with IPv4. As of this writing, most sessions are created manually from unicast-prefix based address space [6], or use SDR to form a semi-random address. Nevertheless these addresses cannot fit with embedded-RP [11] which is the only existing solution for IPv6 interdomain ASM. Some people argue that SSM solves the problem but there is nowadays a demand from customers to be capable to have multicast sessions (both IPv4 and IPv6) with multiple sources (e.g., conferencing) and it is not clear how to achieve this with SSM. While "multiple-source SSM" could potentially be done with the aid of SIP or RTP, this does not exist yet, and a simple solution for ASM is needed." 1.2 Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [1]. 1.3 SSM: no solution needed In the SSM model, as the channel is defined by the tuple (source address , group address), a collision can only occur if a host would like to be a sender for 2 different groups having the same address. Durand Expires August 19, 2005 [Page 3] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 Therefore, it is sufficient for a sender to choose different addresses for different channels, this is a decision local to the host. This document only considers the ASM model which is a bit more complex. 1.4 Session announcement considerations This document does not address the session announcement problem. It only answers the question of large scale address assignemnt of IPv6 multicast addresses. Announcement of the sessions can still be done using web pages, emails, directories, SAP, etc. 2. State of the art for address assignment MADCAP [2] solves, or could solve, the multicast address assignment problem for both IPv4 and IPv6. However, MADCAP is a fork of DHCP, it has only a couple of implementations which have not been widely deployed. We assume that a mechanism that would be a simple extension to a more widely available mechanism (DHCPv6) could be more deployed. This proposal and draft-jdurand-ipv6-multicast-ra [14] simplify the assignment architecture since the unicast and multicast address assignment mechanisms become the same. We consider at this stage only IPv6 multicast since most of the key elements used are already defined, and interaction with IPv4 multicast is ensured. If felt needed by the community, this proposal could be extended to IPv4. 3. Assignment with DHCPv6 3.1 New DHCPv6 options This section introduces new options for IPv6 multicast address assignment with DHCPv6. 3.1.1 IA_MA option for IPv6 Multicast Addresses RFC 3315 [8] defines the following options for Identity Associations (IA): o IA_NA option for Non temporary Addresses o IA_TA option for Temporary Addresses This document introduces a third option: the IA_MA option for IPv6 Multicast Addresses. This option is used to carry an IA_MA, the parameters associated with the IA_MA, and the addresses associated with the IA_MA. The format of the IA_MA option is: Durand Expires August 19, 2005 [Page 4] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | option-code | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IAID (4octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . IA_MA-options . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code: OPTION_IA_MA (TBD) option-len: 4 + length of IA_MA-options field IAID: The unique identifier for this IA_MA; the IAID must be unique among the identifiers for all of this client's IA_MAs. The number space for IA_MA IAIDs is separate from the number space for IA_NA and IA_TA IAIDs IA_MA-Options: Options associated with this IA_MA The IA_MA-options field encapsulates those options that are specific to this IA_MA. For example, all of the IA Address Options carrying the multicast addresses associated with this IA_MA are in the IA_MA-options field. Each IA_MA carries one "set" of multicast addresses; that is, at most one address per session created by the client requiring an address. An IA_MA option may only appear in the options area of a DHCP message. A DHCP message may contain multiple IA_MA options. The status of any operations involving this IA_MA is indicated in a Status Code option in the IA_MA-options field. Note that an IA has no explicit "lifetime" or "lease length" of its own. When the valid lifetimes of all of the addresses in an IA_MA have expired, the IA can be considered as having expired. An IA_MA option does not include values for T1 and T2 (see RFC 3315 [8]). A client MAY request that the lifetimes of multicast addresses be extended by including the addresses in a IA_MA option sent in a Renew or Rebind message to a server. For example, a client would request an extension on the lifetime of a multicast address to allow an application to continue a multicast session. The client obtains new multicast addresses by sending an IA_MA option Durand Expires August 19, 2005 [Page 5] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 with a new IAID to a server. The server will generate new multicast addresses and return them to the client. In case the clients needs to extend the multicast session, it sends a Renew message to the server with the IA_MA and addresses in parameters. 3.1.2 Scope Option for IPv6 multicast address The scope option for IPv6 multicast addresses is used by the clients to request multicast addresses with a certain scope. It is included in the IA address option IAaddr-options field defined in section 22.5 of RFC 3315 [8]. A user can attach more than one scope option for IPv6 multicast address to an IA address option if the client does not know exactely the scope it wants to request but has a set of adequate scope values. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_SCOPE | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | scope | res | +-+-+-+-+-------+ option-code: OPTION_SCOPE (TBD) option-len: 1 scope: The scope value for the requested IPv6 multicast address, according to values defined in RFC 3513 [9] res: This field is reserved for future use. The 4 bits of this field MUST be set to 0, and MUST be ignored on receipt 3.2 Address timers NOTE: There have been some discussions about using some options for the timers. This is let to next releases of the document as this release really focuses on why an assignment based on DHCPv6 has an interest. The IA address option defined in RFC 3315 [8] contains the following 32 bits fields: o preferred-lifetime: The preferred lifetime for the IPv6 address in the option, expressed in units of seconds o valid-lifetime: The valid lifetime for the IPv6 address in the Durand Expires August 19, 2005 [Page 6] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 option, expressed in units of seconds We suggest to use these fields, usually defined for unicast addresses, for IPv6 multicast addresses, with the definition written above. The maximum value for these lifetimes is 2^32 seconds or 49710 days equivalent to 136 years. Therefore a host that wants to be assigned an address for a 2 days session occuring in 30 days can request an address with a preferred lifetime value of 32 days. According to the IPv6 multicast addressing space available, servers should allow this type of requests, or at least should permit a certain number of long-term assignment per host. The address is directly assigned by the DHCP server when the request is received. We suggest here not using the parameters minDesiredStartTime and maxDesiredStartTime specified in RFC 2771 [3] which bring too much complexity for the assignment and don't really make sense for IPv6 where many addresses are available. 3.3 Assignment of a multicast prefix The assignment of a multicast prefix can be needed in the following scenarios: o An ISP needs to assign a block of IPv6 multicast address to an enterprise, assigning IPv6 multicast addresses to its hosts. This scenario will most likely occur when DHCPv6 prefix delegation [10] is already used to assign unicast prefixes to the enterprise. o Also it is most likely that the multicast applications will not support at the beginning the API to request for an IPv6 multicast address via DHCPv6. Then, on startup, or when connected to a new network, a host could ask for an IPv6 multicast prefix. Applications could then choose locally multicast addresses in the prefix assigned to the host. To fulfill this need, the prefix delegation mechanism described in RFC 3633 [10] is needed also for multicast prefixes. The actual specifications of the IPv6 prefix Options for DHCPv6 do not need to be changed to support multicast prefix delegations. The only thing to keep in mind is that multicast prefix delegation can also occur between a router and a host to fulfill the second requirement mentioned above. 3.4 Client and server behavior The procedures to request an IPv6 multicast address is more or less the same than the ones described in RFC 3315 [8] to request a Durand Expires August 19, 2005 [Page 7] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 temporary IPv6 address. The differences are following: o The client uses IA-type IA_MA described above to ask for IPv6 multicast addresses. o The client SHOULD use the Scope Option in solicit and request messages to tell the server the scope wanted for the IPv6 multicast address requested. It can include more than one Scope Option for IPv6 multicast address per addresses requested in case the client does not know exactly the scope it wants to request but has a set of adequate scope values. o The client SHOULD specify the lifetimes for every address it wants to be assigned in solicit, request, renew and rebind messages. o The server MUST assign addresses only if it can assign an address matching one of the scope requested. In case the server can't assign an address with the requested scopes, it must include the Status Code Option NoAddrsAvail in the advertise and reply messages and should include a status message with the scopes that can be assigned by the server and their description. o If no scope option is specified by the client, the server can assign a multicast address with any scope. It can be a default scope value configured by the DHCP server administrator. 4. Group-ID consideration RFC 3307 [7] defines guidelines for the choice of IPv6 multicast group identifier (the last 32 bits of the IPv6 multicast address). It specifies that for dynamic IPv6 multicast address allocation, the group-ID MUST be in the range 0x80000000 to 0xFFFFFFF. 5. Deployment scenarios - Case studies This section gives examples of DHCPv6 deployments for IPv6 multicast address assignment. 5.1 Scenario 1: Site deployment Consider a site having configured a DHCPv6 server and having one RP for a site-local scope (scope 5). In this simple scenario, the DHCPv6 server can assign the complete set of addresses with a site-local scope. We have the same scenario if the site configures one RP for global scope with embedded-RP technology. The DHCPv6 server of the site can Durand Expires August 19, 2005 [Page 8] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 assign the complete set of addresses derived from the RP's address (see Embedded-RP [11]). 5.2 Scenario 2: Campus deployment Consider a campus having configured one DHCPv6 server for the entire site, and having several labs (in different subnets) having each a multicast scope for their own usage. Every lab might have for example a scope admin-local (scope 4), and the campus may have the scope site-local (scope 5). The problem of the DHCPv6 server is to assign appropriate addresses to each of the labs. The server can retrieve information about the location of the client according to the explanation given in section 11 of RFC 3315 [8]. The server can determine this way in which lab the client is and assign adequate addresses. This way a server can assign the same address twice to different clients in different labs. 5.3 Scenario 3: ISP deployment Consider an ISP providing a global RP service to its customers. The ISP decided to use embedded-RP technology for this RP. Every customers having configured a DHCPv6 server would like to assign IPv6 multicast addresses based on the RP of their ISP. The problem is to avoid overlap between addresses assigned by every DHCPv6 servers. In this scenario, the ISP having configured an RP would allocate a range of IPv6 multicast addresses based on its RP to every customer having subscribed for the service (as explained in section 5.2 of Embedded-RP [11]). This allocation could be typically hand-off allocation, as it is done between ISP and big customers (not end-users at home) for unicast or could be done with DHCPv6 prefix delegation as explained in this document. This way, every DHCPv6 server is then configured with a different multicast address range, all matching the same RP. This means that ISPs need to allocate IPv6 multicast addresses to their customers, as they do today for IPv6 unicast. Address allocation architectures are exactly the same. Nevertheless, we can note that any customer could deploy its own embedded-RP rather than using the one of its ISP, which simplifies this scenario. 6. Security considerations The security considerations related to the DHCPv6 protocol are discussed in the security considerations section of [8]. Durand Expires August 19, 2005 [Page 9] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 7. Acknowledgement The author would like to thank Bernard Tuy, Stig Venaas, Christian Strauf, Pekka Savola and Dave Thaler for their good contributions to this memo. The author would also like to thank Ralph Droms who took time to consider the IPv6 multicast assignment problem and introduced the concept of the identity association for IPv6 multicast addresses. The author would also like to thank all the people having worked on the 6NET Deliverable 3.4.3 [12], which was the initial document that raised the complete problematic of IPv6 multicast address assignment. Pekka Savola, Dave Thaler, Stig Venaas and Bernard Tuy have contributed to better state the problem and mention why the proposal is of interest. 8. Discussions Here are the current discussions and questions about this document: o Timers could be specified with a new DHCPv6 option rather than overloading the timers of the address o If the server cannot assign addresses for the required scopes, it could assign an address in any other scope it is configured for. 9. Changes from -00 o Clarification of the need for the proposal o The multicast address assignment state of the art is now let to ID.draft-ietf-mboned-addrarch [13]. o IPv6 multicast prefix delegation is now supported by this mechanism, from comments received in IETF 60th. 10. References 10.1 Normative references [1] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [2] S. Hanna, B. Patel and M. Shah, "Multicast Address Dynamic Client Allocation Protocol (MADCAP)", RFC 2970, December 1999. [3] R. Finlayson, "An Abstract API for Multicast Address Durand Expires August 19, 2005 [Page 10] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 Allocation", RFC 2771, February 2000. [4] M. Handley, C. Perkins and E. Whelan, "Session Announcement Protocol (SAP)", RFC 2974, October 2000. [5] D. Meyer and P. Lothberg, "GLOP Addressing in 233/8", RFC 3180, September 2001. [6] B. Haberman and D. Thaler, "Unicast-Prefix-based IPv6 Multicast Addresses", RFC 3306, August 2002. [7] B. Haberman, "Allocation Guidelines for IPv6 Multicast Addresses", RFC 3307, August 2002. [8] R. Droms, J. Bound, B. Volz, T. Lemon, C. Perkins and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [9] R. Hinden and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3513, April 2003. [10] O. Troan, R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003. [11] P. Savola and B. Haberman, "Embedding the Rendezvous Point (RP) Address in an IPv6 Multicast Address", November 2004. 10.2 Informative references [12] 6NET project partners, "6NET D3.4.3 - IPv6 multicast address allocation study", May 2003. [13] P. Savola, "Overview of the Internet Multicast Addressing Architecture", November 2004. [14] J. Durand and P. Savola, "RA for IPv6 multicast prefixes", February 2005. Durand Expires August 19, 2005 [Page 11] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 Author's Address Jerome Durand GIP RENATER 151 Bd de l'Hopital Paris 75013 France Phone: +33 1 53 94 20 30 EMail: Jerome.Durand@renater.fr Durand Expires August 19, 2005 [Page 12] Internet-Draft IPv6 multicast address assignment with DHCPv6 February 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the IETF's procedures with respect to rights in IETF Documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society.</pre>

IPv6 multicast address assignment with DHCPv6

Tukiyooo 0 19:10

Network Working Group J. Durand Internet-Draft GIP RENATER Expires: August 19, 2005 February 18, 2005 IPv6 multicast add… Read more »

Read more »