R1 is configured with the default configuration of OSPF. From the following list of IP addresses configured on R1, which address will the OSPF process select as the router ID?

The correct answer is A. 192.168.0.1. OSPF selects the Router ID using this priority order: (1) a manually configured 'router-id' command, (2) the highest IP address on any loopback interface, (3) the highest IP address on any active physical interface. Without a manual configuration or loopback interfaces, OSPF…

Implement a Scalable OSPF Based Solution

Question

R1 is configured with the default configuration of OSPF. From the following list of IP addresses configured on R1, which address will the OSPF process select as the router ID?

Options

A192.168.0.1
B172.16.1.1
C172.16.2.1
D172.16.2.225

How the community answered

(44 responses)

A
93% (41)
C
5% (2)
D
2% (1)

Explanation

OSPF selects the Router ID using this priority order: (1) a manually configured 'router-id' command, (2) the highest IP address on any loopback interface, (3) the highest IP address on any active physical interface. Without a manual configuration or loopback interfaces, OSPF selects the highest IP address among all active interfaces. Comparing the options: 192.168.0.1 (192.x.x.x) is numerically higher than all 172.16.x.x addresses. Therefore, 192.168.0.1 is selected as the OSPF Router ID. Note that 172.16.2.225 is higher than 172.16.2.1 and 172.16.1.1, but all 172.x addresses are lower than 192.168.0.1.

Topics

#OSPF router ID#router ID selection#highest IP address#loopback interface

Community Discussion

No community discussion yet for this question.

Full 200-101 Practice