A quick guide to setting up a IPv6 Tunnel using public 6to4 relays under GNU/Linux

Setting up a 6to4 tunnel will allow IPv6 (or dualstack) hosts on networks that only have Public IPv4 addresses to access sites and services that are available via IPv6. The main steps are calculating the IPv6 version of your Public IPv4 address; establishing a 6to4 tunnel to one of the free IPv6 relays available; and configuring the local network to route IPv6 via the tunnel.

Overview of the Topology




Half-arsed Home Cisco Lab

For a little bit of extra practice before the CCNA exam, I hooked up a small lab with a couple switches bridged to emulated routers (running under GNS3 on the laptop). The reason for the multiple trunks between the switches was to test out Spanning Tree. I was going to setup link aggregation as well, but the 3500XL didn't want to play ball. I found out later that it doesn't support PAgP or LACP, so the method for setting up aggregation is different.

VTP and CDP worked properly overly the bridged link - as they should, but I was expecting something to go wrong for some reason (pessimism?). Minicom also played ball with the USB-to-serial adapter (for the console cable), which is always handy too :)