OSPF Router Setup

Let's annotate the following as A — B — C router

On router A

• en
• config t
• int Gi0/0
• no switchport — to convert it to L3 interface (able to handle IP)
• ip address 10.0.0.4 255.255.255.0 — assign 10.0.0.4/24

On router C

• en
• config t
• int Gi0/0
• no switchport — to convert it to L3 interface (able to handle IP)
• ip address 10.0.0.5 255.255.255.0 — assign 10.0.0.5/24

On router B

• en
• config t
• int Gi0/0
• switchport mode access — change it to taking a vlan only
• switchport access vlan 10
• int Gi0/1
• switchport mode access — change it to taking a vlan only
• switchport access vlan 10

Confirmation

• On router B:
  • show vlan — make sure that Gi0/1 and Gi0/0 are in vlan 10
• On router A and C:
  • Try to ping eachother ping 10.0.0.5 and ping 10.0.0.4 and make sure that they're ok

Next we will setup ospf

On router A

• en
• config t
• router ospf 1 — chosing a random ospf ip (1)
• network 10.0.0.0 0.0.0.255 area 0 — setting 10.0.0.0/24 to be included in ospf
• exit

On router B

• en
• config t
• router ospf 1 — chosing a random ospf ip (1)
• network 10.0.0.0 0.0.0.255 area 0 — setting 10.0.0.0/24 to be included in ospf
• exit
Now we should be able to see the ospf router when doingshow ip ospf neighbor` on router A and B

Switch#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.0.0.5          1   FULL/DR         00:00:37    10.0.0.5        GigabitEthernet0/0