Gentoo IPv6 Router Guide

-Using 6to4 Conversion -

-Basic principles - - -

-6to4 conversion can be used if you want to have hosts that talk to IPv4 -hosts over a purely IPv6 connection. Thus you can have an entirely IPv6 -internal network, with one host dealing with connecting to the outside -IPv4/IPv6 world. -

- - -

- -

-DNS configuration - - -

-To get 6to4 conversion working, a DNS proxy, totd, needs to be -configured that will send you AAAA records for sites that really only ha= ve -A records. These AAAA records will point to IPv6 addresses which don't -actually exist, but which will get routed through a 6to4 proxy. -

- -

-First, install totd: -

- -

-# emerge totd
-

- -

-Next, we need to setup /etc/totd.conf with some basic -configuration information. -

- -

-(Points to a real DNS nameserver)
-forwarder 192.168.0.2 port 53
-(What prefix to put before faked AAAA records)
-prefix 3ffe:abcd:1234:9876::
-(What port to run totd on)
-port 5005
-(What PID file to use)
-pidfile /var/run/totd.pid
-(Actually do 6to4 stuff)
-stf
-

- - -totd must be set to use a port different than port 53 if another -nameserver is running on the same machine. - - - -

- -

-6to4 proxy - - -

-ptrtd will be used as a 6to4 proxy, enabling connections between -the internal IPv6 host and the outside IPv4 host. -

- -

-# emerge ptrtd
-

- -

-We now need to configure ptrtd, telling it what fake prefix -(the one we setup totd to use) to create proxy connections for. -Edit /etc/conf.d/ptrtd and set IPV6_PREFIX. This -should be the same prefix as was configured with totd. -

- -

-IPV6_PREFIX=3D"3ffe:abcd:1234:9876::"
-

- -

-You can now start totd, and enable it to start at boot. -

- -

-# /etc/init.d/totd start
-# rc-update add totd default
-

- - -

- -

-Client configuration and testing - - -

-Clients may now be configured to connect to both IPv4 and IPv6 hosts -through an IPv6 only connection. Assuming that the clients are already -receiving an IP address from radvd, we simply need to add a new DNS -resolver entry, and add a default route for those "fake addresses". -First, add an entry at the top of your /etc/resolv.conf -pointing to the machine running totd. -

- -

-nameserver 2001:470:1f00:296::1 (The server running totd)
-

- -

-To test name resolution, request an AAAA record for a known IPv4 -only site. -

- -

-# dig aaaa google.com
-;; ANSWER SECTION:
-google.com.             300     IN      AAAA     3ffe:abcd:1234:9876::d8=
ef:3364
-google.com.             300     IN      AAAA     3ffe:abcd:1234:9876::d8=
ef:3564
-

- -

-We will now add a default route for all addresses prefixed with our -chosen fake prefix. -

- -

-(Assuming your IPv6 interface is eth0)
-# ip route add 3ffe:abcd:1234:9876::/64 via 2001:470:1f00:296::1 dev =
eth0
-

- -

-Finally, use ping6 to ping google.com at it's fake IPv6 location. -

- -

-# ping6 -c 2 google.com
-PING 3ffe:abcd:1234:9876::d8ef:3364(3ffe:abcd:1234:9876::d8ef:3364) 56 d=
ata bytes
-64 bytes from 3ffe:abcd:1234:9876::d8ef:3364: icmp_seq=3D1 ttl=3D54 time=
=3D0.106 ms
-64 bytes from 3ffe:abcd:1234:9876::d8ef:3364: icmp_seq=3D2 ttl=3D54 time=
=3D0.090 ms
-
---- 3ffe:abcd:1234:9876::d8ef:3364 ping statistics ---
-2 packets transmitted, 2 received, 0% packet loss, time 1000ms
-rtt min/avg/max/mdev =3D 0.090/0.098/0.106/0.008 ms
-

- - -The router running ptrtd is actually replying, but this at least -tells us things are working. - - - -