Re: possible misunderstanding of rtadvd providing ipv6 IPs of prefixlen 80

Le 08/12/2010 6:36 PM, Forman, Jeffrey a icrit :
> My ISP (Comcast) has started an IPv6 trial where their customers can tunnel
> ipv6 traffic over ipv4 through Comcast infrastructure for ipv6 connectivity.
> We're given a /64 to play with, in my context I have 2001:55c:dead:beef/64
> (dead:beef inserted to obscure the innocent). My OpenBSD 4.8 router/fw is
> configured with the gif0 interface as 2001:55c:dead:beef::1. This works
> great from the openbsd fw itself. I can access ipv6 sites, traceroute6,
> ping6, etc etc.
>
> Now I am trying to hand out IPv6 addresses to my local LAN (mix of Linux,
> Free/OpenBSD, and OSX boxes) to eventually provide them all with IPv6
> connectivity out to the Internet. I figured i would carve out a /16 of
> addresses for my home LAN under the subnet 2001:55c:dead:beef:10::/80.

Stop right there. This cannot work.

comcast --------<tunnel>------- OpenBSD ---------<LAN>---------...
         2001:55c:dead:beef::/64         2001:55c:dead:beef:10::/80

The address range you assign to your LAN overlaps with the address range 
assigned to the tunnel.

You need non-overlapping ranges.

Usually, tunnel brokers give out two prefixes: one for the tunnel, and 
another for your LAN (see e.g. Hurricane Electric).

Simon