Not re-exporting learned OSPF routes

[Ondrej Zajicek]

On Fri, Jun 07, 2013 at 08:07:59PM -0400, Ryan Whelan wrote:
> I feel like this should be simple, but I can't find what I'm looking for...
> 
> I have a few of routers spread across the country in a full mesh running
> OSPF.  'Servers' and 'clients' connect to these 'routers' to connect to one
> another- each 'server' and 'client' run a basic bird instance they use to
> share a local address (X.X.X.X/32).  The issue is some of the 'servers'
> connect to multiple 'routers' so if a link between 2 routers is down, OSPF
> tries to route though a server... ('servers' don't have ip forwarding on)
> 
> In short, how do I make sure the 'servers' can run bird to update OSPF with
> their /32 address but not re-propagate routes they learn from OSPF (so as
> to not be considered for route selection by the routers)?

Hello

OSPF works in a different way, there is no 're-propagation of routes' in
OSPF, OSPF works by mapping network topology and then everyone
calculates shortest paths. Every OSPF node is a part of a network
topology and it is implicitly assumed to be a router. There is an
extension that allows non-routing OSPF node to participate without
acting as a transit node (RFC 3137), but this is not implemented in
BIRD.

There are some ways to solve your problem:

1) use OSPF only between routers and use a different protocol between
servers/clients and routes.

2) use multiple OSPF instances (with different router ID) on servers,
one instance for one link to a router, but there would be problems if
you would need to share an iface between OSPF instances.

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: Digital signature
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20130610/b6e852ef/attachment-0001.asc>