On 17.09.2012 17:06, Ondrej Zajicek wrote:
On Mon, Sep 17, 2012 at 01:29:35PM +0600, Eugene M. Zheganin wrote:
Hi.
Why bird touches on-interface routes ? Right now I have to create import filters and prohibit importing of on-interface routes, because in case of losing a link bird thinks that this route was added by it and deletes it, making the network unuseable. Is there a way to tell it 'don't touch on-interface routes' ?
BIRD tries to not touch these routes, so it is strange that in your case these routes are removed.
First, device routes (and their removal) are not exported to kernel unless 'device routes' option is active. But this can be circumvented when protocol tries to export 'regular' route (with next-hop) for the same network (this is probably what happened if you have OSPF and two routers connected to a network, one loses a link and tries to route to that network through the other router). Workaround for this is to have active 'direct' protocol, which generates local routes with higher priority, so any OSPF route for that prefix is not propagated to the kernel. This workaround still has problems in case of direct* patterns reconfiguration.
Unfortunately, I can't think of any good bird-side patch to fix this in better way. I'm planning to fix this in FreeBSD kernel, but it is a long story.. Can we update Direct protocol documentation to reflect this problem?
Second, kernel protocol do not overwrite any non-BIRD route in kernel routing table. But AFAIK this works only on Linux, not in BSD. So i guess you use BSD?
Yes.