ipv6 in ipv6 tunnel with FreeBSD 4.11

[gnn at freebsd.org]

At Fri, 18 Aug 2006 15:28:11 +0000 (GMT),
Julien Abeillé wrote:
> Hi,
>  
>  I am using freebsd 4.11 and trying to setup ipv6 in ipv6 tunnels.

All my stuff is on HEAD and 6 so I don't know if this applies but I
think it should.

>  I have the following testbed
>  4 machines connected in line:
>  
>  M1-----------M2--------FreeBSD-------M3
>     c::1---c::2  |  b::2----b::1   |   a::1---a::2
>  
>  I want to create a tunnel between FreeBSD (b::1) and M2 (b::2)
>  
>  Here is my configuration on the FreeBSD machine:
>  em0 : a::1/64
>  em1 b::1/64
>  
>  I do the folllowing to setup the tunnel:
>  
>  ifconfig gif0 create
>  ifconfig gif0 tunnel b::1 b::2
>  ifconfig gif0 d::1/64
>  route add -inet6 -host c::1 -interface gif0
>  
>  I am not sure about what is the gif0 address d::1/64 used for.
>  

Nor am I.  What directions are you following?  I believe that may be
there because the gif tunnel instructions talked about setting up IPv4
tunnels for IPv6.

>  the problem is: when i ping or send any traffic from a::2 to c::1,
>  the FreeBSD machine adds an ipv6 header with b::1 as source, b::2 as destination, but with hop count limit=0
>  
>  Is my configuration ok? 

A few things to note:

1) You need to have

ipv6_gateway_enable="YES"

set to forward packets.

2) Are you trying to tunnel between two interfaces on the same
   machine?  It's hard to tell from your description.  If the FreeBSD
   box is a router between two tunnels then you need two tunnel
   endpoints.  One pointing at M2 and one pointing at M3.

Best,
George