On Thu, Nov 04, 2010, Ondrej Zajicek wrote:
Although i agree with Joakim Tjernlund and others that link state change detection is useful to get faster response to internal network unreachability. I think that in your case you would need something slightly different.
I understand that you have some (probably static) routes with gateway accessible through given (external) interface and you want to detect unreachability of the (external) gateway to add/remove that (static) routes.
Yep, exactly. The static is then repropagated into the OSPF table, and a remote area with the same setup acts as failover.
Detecting a link state is crude, because there might be many other kinds of problems that does not change link state.
Agreed, although I'd maintain that in no case should a lack of link be a valid condition for bird to think the interface is available, regardless of the potential for other network problems.
I would suggest to use some shell/perl script that ping to the gateway and according to its reachability it will enable/disable static protocol (with routes using that gateway) in BIRD.
I completely missed that birdc had that capability. Neat.
I plan to implement a link state change handling, but it will take some time, it is definitely more complicated than the patch you sent (for example, it should differentiate between administrative up/down and link state up/down).
That's great to hear. I certainly didn't assume my patch would be used, I've just always thought it more polite to try when requesting a feature. Thanks for your attention to it. -- Mahlon E. Smith http://www.martini.nu/contact.html