OSPF Single Area

Configuration:

• Enable Globally
  • ‘router ospf <process id>’
  • Network statements with IPs/wildcard masks
    • ‘network 0.0.0.0 0.0.0.0 area <area #>
• Enable Under Interface
  • ‘ip ospf <process id> area <area #>
  • If a manual router ID is needed, needs to be entered under the ‘router ospf <process id>’ configuration.
  • This enables OSPF for both primary and secondary IP addresses.
  • OSPF stays enabled even when IP address changes.

• Verification basics:
  • ‘show ip ospf’
  • ‘show ip ospf int brief’
    • Quick way of showing which interfaces are enabled, which area each interface is in.
  • ‘show ip ospf neighbor
  • ‘debug ip ospf adjacency’
  • ‘show ip ospf database’

Below there are two routers running OSPF.

R2:
– Gig0/0 – 10.30.1.2 255.255.255.252
– L0 – 10.30.2.1 255.255.255.0
– L2 – 10.30.3.1 255.255.255.0

R1:
– Gig0/0 – 10.30.1.1 255.255.255.252
– L0 – 172.16.1.1 255.255.255.0
– L1 – 172.16.2.1 255.255.255.0

R1 OSPF Config:

R2 OSPF Config:

R1 Verification/Routing Table:

R2 Verification/Routing Table: