Hi All, I'm wondering if anyone has found an elegant solution to the problem I'm having with interaction between CARP and OSPF. I have a pair of routers in a failover config. On one side they speak OSPF to a set of other routers and on the other side use CARP to provide a default gateway to a set of hosts. There is currently only one CARP interface at the moment whilst I'm testing this setup, but once in production there will be around 50-60 vlan interfaces, each with a CARP interface.
Failover works a charm and if I reboot the primary then the backup takes over in around 1 second. However when the primary boots back up and tries to take over then I lose connectivity for about 12-14 seconds. What I think is happening is that the CARP side is becoming master before the OSPF side has had a chance to work out neighbors and take over as the preferred route for packets. I know that OSPF can be configured to demote the carp group until it has at least one active neighbor, but this is too late. The carp interface is brought up on boot before the ospfd is started. Anyone know of a good way to solve this? I'm guessing something along the lines of demote the carp group *before* the carp interfaces are brought up (is that even possible?) and then remove the demotion once OSPF has stabalised. I don't see a nice clean place in the startup process to do this though unless I hack /etc/netstart or similar which I don't want to do. Thanks, -Matt
