[nsp] ospf (cisco and zebra)

[Ryan O'Connell]

On Tue, 29 Oct 2002 14:21:09 -0800 (PST) Mark Kent <mark@noc.mainstreet.net> wrote:
> Hello,
> 
> I've got a cisco/ospf/zebra query...
> 
> The facts:
> 
>   two freebsd boxes on a fastethernet sub-interface (802.1q)
>   serviced by a cisco7206.
> 
>   freebsd boxes have the same set of IP addresses, X, attached to their
>   loopback interfaces.
> 
>   freebsd boxes run ospf using zebra
> 
> The goal:
> 
>   one freebsd box to be preferred for packets destined for X
>   (from the point of view of the cisco7206).
>   The other one would not get any packets destined for X 
>   delivered to it.

Make sure your two Zebra boxes have different OSPF router IDs or Bad Things
will happen. (ospf router-id x.x.x.x) By default it may use the loopback
IPs, which are the same on both boxes. I couldn't find any documentation
online as to how Zebra chooses OSPF router Ids but this is the way Cisco
does it and Zebra is very much a Cisco routing clone.

Then, set different ip ospf costs on the FastEthernet interfaces of the
FreeBSD boxes. This will allow you to influence which box is primary and
which is secondary.

-- 
      Ryan O'Connell
Mail: ryan@complicity.co.uk
  CV: http://www.complicity.co.uk/ryancv.pdf
      CCIE #8174