Ospf router-id command cisco

OSPF is a Link State Routing Protocol.

Ospf router id highest ip address

Ospf router id highest ip address

Ospf router id priority

What is router id in ospf

Bgp router id

How to change router id in ospf

In this method of Routing the Router shares its neighbor knowledge with everyone in the router. In OSPF one router is elected as Designated Router and one router is elected as Backup Designated Router(BDR). They are elected so that we can control how much repetitive information is forwarded over the network.

Every Router in the network reports to the DR and the DR forwards the information to other routers in the network.

OSPF uses multicast addresses 225.0.0.6 and 225.0.0.5.

Router ID in OSPF:

1. It is a 32-bit identity of a router used to identify a router in a network.
2. Used in DR/BDR election.
3. It is unique in an autonomous system.

Router-ID Election:

1. Manually configured in OSPF.
2. The highest IP is provided to a loopback interface.
3. Highest IP provided to an active interface

Configuration:

Consider the topology:

Configuring R0:

interface GigabitEthernet0/0/0
ip address 10.0.0.1 255.255.255.252
no shutdown
interface GigabitEthernet0/0/1
ip address 172.16.1.1 255.255.255.252
n

check router id