Nimbostratus
Nimbostratus
Thanks for the reply.
Please see my response to your questions under mentioned -
- do you have active routes to F5 when cut starts? If yes, where they point to? => If they are ok, the problem is probably not with routing.
[SAGAR] >> No I donot have the same, I've asked my field guys to collect the same on BigIP when trough occurs. Basically, I've asked them to collect show ip ospf route and show ip ospf database outputs.
- what is the state of neighboring routers? Check if they are not stuck in EXSTART, 2WAY or something similar. Check that on every node You have.
[SAGAR] >> The state of neighbors on every router is Full/DR and Full/Backup which indicates that none of them get stuck halfway in some intermediate states!!!
- who is DR/BDR? Try to force Cisco as DR and BDR by setting priority.
[SAGAR] >> Generally DR/BDR are Ciscos but I've not set any priority on BigIP. It would be a good idea to set ip ospf priority on bigip to zero and force BigIP never to become a candidate for DR/BDR election.
- check dumps if there are some malformed LSAs or something like that.
[SAGAR] >> So far not collected dumps during the cut, waiting for a next cut and include this in my field manual!!
Reason behind running OSPF is that, during deployment we ran into issues when we used auto last hop pool feature and pointed all traffic from internet routers to Cisco 6509s to the pool containing Cisco 6509s as members. The issue was predominantly inaccessibility to internet for the subscribers intermittently!! By populating OSPF on BigIPs this issue was resolved.
I am also in touch with F5 support but so far I've not received a concrete solution to this problem.
/Sagar