Current File : //usr/share/doc/initscripts-9.49.53/ipv6-tunnel.howto
v1.4 10th Jan 2002, Pekka Savola <pekkas@netcore.fi>
HOW TO SET UP AN IPV6 TUNNEL
----------------------------
ASSUMPTIONS
-----------
1. You're running Red Hat Linux 7.1 or later.
This is required for correct IPv6 by default settings, and IPv6 being
enabled as a kernel module by default. You also need recent enough
initscripts, provided in RHL71.
2. You have a static, globally unique IPv4 address.
3. Protocol 41 (IPv6-in-IPv4) is not being filtered in any IPv4 firewall.
4. 'iproute' package is installed. This is used by default for a lot
more powerful tunneling capabilities.
INFORMATION NEEDED
------------------
You need to know:
1. The IPv4 address of your tunnel end point
2. The IPv6 address used in your tunnel
The other end needs to know the same things about your setup.
NOTE: It is also possible to set up unnumbered tunnels (no global IPv6
addresses).
You must get these from a party (tunnel broker) who's assigning IPv6 tunnels. See:
http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO-1.html#joinIPv6backbone
Example from http://old.freenet6.net:
---
This script will create a tunnel between this computer
and the Freenet6 server (tunnels server)
Your IPv6 address (your tunnel end point) is
3ffe:b00:c18:1fff:0:0:0:7f5
We establish a tunnel to the Freenet6 server at
3ffe:b00:c18:1fff:0:0:0:7f4
Your IPv4 address is : 193.xxx.yyy.zzz
The IPv4 address of the Freenet6 server is : 206.123.31.102
---
With this information, a tunnel can be set up:
SETTING UP THE TUNNEL CONFIGURATION
-----------------------------------
Now, set up the configuration as follows:
1. Enable IPv6 and set tunnel as default gateway in /etc/sysconfig/network:
echo "IPV6_DEFAULTDEV=sit1">> /etc/sysconfig/network
2. Create /etc/sysconfig/network-scripts/ifcfg-sit1, with the following:
---
DEVICE=sit1
BOOTPROTO=none
ONBOOT=yes
IPV6INIT=yes
IPV6TUNNELIPV4=206.123.31.102
IPV6ADDR=3ffe:b00:c18:1fff:0:0:0:7f5/128
---
NOTE: You must use _sit1_ (or sit2,...). sit0 cannot be used, this is a
special device.
NOTE: Some tunnel endpoints might require a different kind of prefix length;
for example, Cisco's usually favour /126. Using /0 creates a default route
through that interface.
NOTE: If you're not directly connected to the Internet, you may want to use
ONBOOT=no instead.
TUNNELING
---------
Tunnel can be brought up and down with:
ifup sit1
ifdown sit1
NOTE: In initscripts < 6.02 (ie. IPV6_TUNNELMODE=NBMA), even though sit1 is used,
'ip' sees the tunnel as sit0. This is due to an "interesting" implementation
of tunneling -- else multiple tunnels couldn't be used extensibly.
NOTE: iproute tools give more reliable data, try e.g. '/sbin/ip addr ls'.
MORE INFORMATION
----------------
http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html is a good
source of IPv6 related Linux-information.
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