Use ospfd's built-in monitoring and debugging commands:
$ telnet localhost 2604
ospfd1> show ip ospf
ospfd1> show ip ospf interface
ospfd1> show ip ospf database
ospfd1> show ip ospf database self-originate
ospfd1> show ip ospf route
ospfd1> enable
ospfd1# debug ospf zebra
ospfd1# debug ospf lsa
ospfd1# debug ospf ism
show ip ospf interface
displays information on all network interfaces. You may specify one
like this:
ospfd1> show ip ospf interface eth2
In addition to these, don't forget your old reliable Linux standbys such as netstat, route, traceroute, ping, and ip. See Chapter 19 for more information on finding and fixing problems.
Quagga documentation: http://www.quagga.net/docs/docs-info.php
man 8 ospfd