RE: network problems

>
> The problems are similar to http://lists.freebsd.org/pipermail/freebsd-current/2009-August/010287.html
>

  That was a configuration issue.

> 
> When I try to ping the address the machine panics!
> (something with sin_family and in_lltable_lookup)
> http://denisy.dyndns.org/panic.jpg
>

  After a quick cursory read over the code, this issue appears to be a problem 
  in the flow-table handling logic in ip_output() function.

  Two problems seem to exist in the flow-table logic.

  1. In flowtable_lookup() where it searches for the destination in the 
     routing table, the code does not check for the rt_ifp type once a
     route entry is found. In the case of "if_tun", the flow-table 
     must not try to cache any entry whose "rt_ifp->if_flag & IFF_POINTOPOINT"
     is true. Right now it does, and I think this will trigger the crash
     later.

  2. The flowtable_lookup() seems to alway assume a valid entry 
     will be returned as long as a route entry exists for the
     destination. In other words, if a route exists for the destination,
     then either flow-table already have a cache, or a new entry
     is created.  This does not work due to (1.) above. 
     flowtable_lookup() should allow a "bypass flow-table" return, not 
     just success/failure result.   This is especially true for
     tunneling interfaces "if_tun, if_gre" etc. where ip_output()
     will be called multiple times (nested). Only at the final invocation
     of ip_output() (where the rt->rt_ifp points to a physical NIC)
     should a flow-table entry be created.

  So for now, as a possible temporary workaround, disable FLOWTABLE in your
  kernel configuration file and see if that fixes the problem.

  -- Qing