Thus spake Brian
This popped up today when I needed to add an NM-4T to our Cisco 3620, which is set to the highest OSPF priority so that it normally becomes the DR, and our 2611 becomes the BDR. Power cycling to add the NM-4T made this swap, of course, so right now the 2611 is the DR and the 3620 is the BDR. Normal enough...
If I remember right it doesn't work like that. When you have a DR and a BDR, and you reboot the DR, yes the BDR becomes the DR. But then when the "old" DR comes back up it does not become BDR. You have to reboot your other box (the original BDR , now DR) for this too happen. In other words, the cluenote I remember is "2 reboots are necessary for a re-election of OSPF DR/BDR".
This may be Ciscocentric, I don't remember.
No, this is standard OSPF, but I think you're violently agreeing with Mike here. :) Originally the 3620 was DR, the 2611 was BDR, rebooting the 3620 should advance the 2611 to DR, and since I believe those two are the only two eligible DR's on this network for him, for the time the 3620 is down, there would be no BDR, when the 3620 comes back up, and "election" would occur for BDR, which the 3620 would "win" (running unopposed :). So they are swapped from the original. To get back to the 3620 being DR and 2611 being BDR, then, yes, the 2611 would have to be brought down.
However, both the ARCs on the subnet suddenly stopped advertising their IP pools, and stopped listening to advertisements from the other routers... basically quit exchange OSPF routes entirely. Naturally, our dialup customers weren't real happy about this. Rebooting the ARCs got things back into shape - a bit drastic of a solution.
I wonder if somehow the ospf database got fscked. I think OSPF does a "flood" every 30 minutes or so, and rebooting the 3com box would have forced at least an initial flood.
To my knowledge (and I'd have to go back and check the RFC to be sure) once the databases are sync'ed, there are no periodic floods.
Yes, it would appear that fra-ts2 is not establishing adjacency with the DR.......
Which is rather interesting since it should have had an adjacency established long before that (when the thing was still just a BDR, the adjacency shouldn't be affected when a router gets advanced from BDR to DR), unless I misread the posting. -- Jeff McAdams Email: jeffm@iglou.com Head Network Administrator Voice: (502) 966-3848 IgLou Internet Services (800) 436-4456 - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.