OSPF can be a mystery to some. Understanding the default timeouts can be helpful in troubleshooting. Some vendors change these times so it is very important to realize this stuff if you start mixing vendors in your OSPF domains.
10 Seconds
Default OSPF hello timer on broadcast and point-to-point links
30 Seconds
Default OSPF hello timer on nonbroadcast links
40 Seconds
Default OSPF hold timer on broadcast and point-to-point links
120 Seconds
Default OSPF hold timer on nonbroadcast links
30 Minutes
OSPF LSA refresh timer
60 Minutes
OSPF LSA expiration timer
