OSPF Neighbor Relationships

Question 1

What are the OSPF neighbor states?

Answer 1

Down, Init, 2-Way, ExStart, Exchange, Loading, Full

Question 2

What is the Hello Interval in OSPF?

Answer 2

The time between sending Hello packets (default is 10 sec for broadcast & 30 sec for non-broadcast networks)

Question 3

What is the Dead Interval in OSPF?

Answer 3

The time after which a neighbor is declared down if no Hellos are received (default is 40 sec for broadcast & 120 sec for non-broadcast networks)

Question 4

What conditions must match for two OSPF routers to form a neighbor relationship?

Answer 4

Area ID, Hello/Dead Interval, Authentication, Subnet, and MTU

Question 5

What is an OSPF Designated Router (DR)?

Answer 5

A router elected on multi-access networks to reduce OSPF traffic

Question 6

How is a DR elected in OSPF?

Answer 6

Based on the highest OSPF priority, or if equal, the highest router ID

Question 7

What is a Backup Designated Router (BDR)?

Answer 7

A router elected to take over DR duties if the DR fails