How To Setup IPv6

Introduction
************

IPv6 (Internet Protocol Version 6) is the successor, respectively the
replacement, of the current version Internet Protocol, IPv4. The main
problem using IPv4 is the growing shortage of IPv4 Addresses caused by
the growing number of machines added to the internet.

IPv6 fixes a number of problems in IPv4, such as the limited number of
available IPv4 addresses. It also adds many improvements to IPv4 in areas
such as routing and network autoconfiguration. IPv6 is expected to
gradually replace IPv4, with the two coexisting for a number of years
during a transition period.

For this reason ePages supports IPv6 in version 6.0.6 and higher.


Requirements
************

- ePages 6.0.6 or higher
- License containing IPv6 address
- Linux kernel 2.6
- Windows 2003 Server 32 Bit or Windows 2008 Server


Prerequisites - Linux
=====================

- Check if the network interface supports IPv6:

  ip -6 addr show

  If command returns nothing or an error occurs, ask your system
  administrator to add the IPv6 network interface (ip -6 addr add ...).

- Check if the firewall allows IPv6 connections:

  PATH=$PATH:/usr/sbin:/sbin iptables -L

  If not, ask your system administrator to change the firewall settings.

- If you use your own web server (not the web server that comes with
  ePages) and you want to use IPv6 for the web server, check the Listen
  directive in the configuration file (usually httpd.conf). Use 'Listen
  80' (or other port), not 'Listen 0.0.0.0:80' (then only IPv4 is supported).


Prerequisites - Windows
=======================

- Enable IPv6 in Windows OS:

  Control Panel -> Network Connections -> Local Area Connection -> Properties
  -> Install... -> Protocol (Add) -> Microsoft TCP/IP version 6

- Check if the firewall allows IPv6 connections:

  Control Panel -> Windows Firewall

- The IIS has to be unconnected or assigned to the correct IPv6 address if the
  IIS should run with IPv6: 

   Administrative Tools -> IIS Manager -> Default Web Site
   -> IP Address (All Unassigned)


IPv6 Activation
***************

Activate IPv6 either in the setup process or after the setup
process. Windows only supports IPv6 activation after setup, skip to the
respective section.


IPv6 Activation in Setup - Linux
================================

This section shows how to IPv6 during the setup. This works only for
Linux, not for Windows. See section 'IPv6 Activation after Setup' if you
want to enable IPv6 in ePages on Windows.

Enable IPv6 by customizing your install.cnf file prior the installation
process. You can skip the section
"Post Installation" then.

- The installation is defined in "install.cnf".
- Append either ":ip6" to the hostname entry (the hostname has to be resolvable
  to an IPv6 address) or use an IPv6 address directly.
- If IPv6 doesn't work on this machine the installation starts using IPv4.
- If <hostname>:ip6 doesn't resolve to an IPv6 address the installation routine
  will try to get an IPv4 address for that hostname and use that one.
- If that fails too the address ::1 will be used.


IPv6 Activation After Setup
===========================

Environment Variables
---------------------

Windows:

  Set EPAGES_ENABLE_IPv6=1. The environment variable EPAGES_IPLIST must
  contain the IPv6 address or the hostname (whether you use IPv6
  addresses or hostnames in Webinterface.conf) if EPAGES_IPBINDING is
  set.

  - Click the right mouse key on the "My computer" icon.
  - Choose "Properties".
  - On the tab "Advanced" click "Environment variables".
  - To create the variable click "New", then enter name (EPAGES_ENABLE_IPv6)
    and value (1) and save with "OK".
  - If the environment variable already exists, choose the variable from
    the list, click "Edit", enter the new value (1) and save with "OK".
  - Change EPAGES_IPLIST in the same way (if necessary).
  - Reboot the server to take effect of the new variable.

Linux:

  Set EPAGES_ENABLE_IPv6=1. The environment variable LOCAL_IPS must
  contain the IPv6 address or the hostname (whether you use IPv6
  addresses or hostnames in Webinterface.conf) if IP_BINDING is set.

  - Add line "export EPAGES_ENABLE_IPv6=1" to the configuration file
    "/etc/default/epages6".
  - Change EPAGES_IPLIST in "/etc/default/epages6" if necessary.

If EPAGES_ENABLE_IPv6 is unset or 0, application server and request
router only support IPv4. In this case, if application server or request
router are configured to IPv6 in WebInterface.conf, errors will occur.


Host Names and Addresses
------------------------

If a host name is resolved to both IPv4 and IPv6, then the IPv6 address
is used if EPAGES_ENABLE_IPv6=1, otherwise the IPv4 address.

In Windows, "localhost" is resolved to both 127.0.0.1 and ::1.
In Linux, "localhost" is resolved to 127.0.0.1 and "ipv6-localhost" is
resolved to ::1.

If IP binding isn't used, a server can be connected with IPv6 and IPv4
clients if the server is set to IPv6 and has an IPv4 address too.


WebInterface.conf
-----------------
  
All IPv4 addresses can be replaced by IPv6 addresses or relevant host
names. The hostname must be short (without ".") or the result of the
command `hostname --fqdn`.

In section "URLRewrite", line ExceptionHost, an IPv6 address has to be
added in squared brackets, e.g.:

  [URLRewrite]
  ExceptionHost=shop.domain.ex [2001:4bd8:2:2:213:d3ff:fe62:f1f0]

When using IP-Masks the part of the IP following the wildcard ("*") will
be truncated and is considered as the beginning of the IP to be
tested. IPv6 masks must be written in short form, i.e.:
- Left-hand zeros have to be written
- Zero blocks have to be shorten to ::

In case of a mixed IPv4/IPv6 communication beside the IPv4 mask the IPv4
mask in IPv6 notation must also exist, e.g. ::ffff:172.20.24.*.

If you use host names in WebInterface.conf, the corresponding IP entry or
IP mask must also exit.

Host masks as follows are not allowed: [*.epages.de]


epages.conf
-----------

IPv6 addresses can be entered in addition to IPv4 addresses and domain names.


Sybase Configuration
--------------------  

Thy Sybase interfaces file (Linux: $SYBASE/interfaces; Windows:
%SYBASE%\ini\sql.ini) may contain IPv4 addresses, IPv6 addresses or host
names.

For Windows, Sybase recommends to use IPv6 addresses instead of host names, see
http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.dc38421_1500/html/ntconfig/X36043.htm.
Hostnames will be resolved to IPv4 addresses on Windows, i.e. IPv4 is
used if host names are entered in "sql.ini".

If you want to support IPv4 and IPv6, you will need to have entries for
both protocols, e.g.:

DBServer
    master tcp ether revival.sybase.com 17100
    query tcp ether revival.sybase.com 17100
    master tcp ether revival.v6.sybase.com 17100
    query tcp ether revival.v6.sybase.com 17100
 
The "*.res" files in $Sybase/ASE-15_0 can contain IPv6 addresses.


Start ePages with IPv6
**********************

Windows hosts must be rebooted to take effect of the changes.

After starting ePages, check if the services run with IPv6:

Windows:
  netstat -a -n | perl -ne "s/ +/ /g; /TCP.*LISTENING/ && print"

Linux:
  netstat -tulpn

If the web server runs with IPv6, you can use the IPv6 address in square
brackets in the URL, e.g.:

  http://[2001:4bd8:2:2:2e0:7dff:fe76:8613]:80/WebRoot/WebAdapterError.html