OSPF and EIGRP Hello Timings

EIGRP
Hello—Interval time in seconds that a router sends an OSPF hello packet. On broadcast and point-to-point links, the default is 10 seconds. On NBMA, the default is 30 seconds.

EIGRP
EIGRP routers establish adjacencies with neighbor routers by using small hello packets.
Hellos are sent every 5 seconds by default.


•Hold time tells the router how long it should consider the neighbor alive if it has not received any EIGRP packets (Hello, EIGRP updates, etc.)
•Hold time is normally three times the configured Hello interval.
•Both the Hello and Hold time intervals are configurable on a per interface basis, and do not have to match neighbor.
•EIGRP routers exchange routing information the same way as other distance vector routing protocols, but do not send periodic updates.
•EIGRP updates are only sent when a network is added or removed from the topology database, when the successor for a given network changes, or when the locally used metric is updated.