Which IS-IS NET address configuration must be implemented on R3 to establish IS-IS connectivity?

Refer to the exhibit.

An engineer with an employee 10:4350:47:853 is implementing IS-IS as the new routing protocol in the network. All routers in the network operate as Level 2 routers in the same private autonomous system, and the three branches are connected via dark fibre. The engineer has already implemented IS-IS on router R1 with NET address 49.0133.532b.ca14.6915.21311.F40F.1B3a.ba10.00.

Which IS-IS NET address configuration must be implemented on R3 to establish IS-IS connectivity?
A . 49.0133.532b.ca14.6915.21311.f40f.1b4a.bb87.00
B. 49.0135.332b.ca14.6975.28371.1721.1b3b.ca11.10
C. 48.0133.532b.ca14.6915.21311.f40f.1626.bb98.00
D. 49.0133.532b.ca14.6915.21311.1721.1b4a.0013.01

View Answer

Answer: A

Explanation:

IS-IS uses NET addresses to identify each router in the network, and the NET address of each router must be unique. In order for IS-IS to establish connectivity between R1 and R3, the NET address of R3 must be different from the NET address of R1, but it must also follow the same structure. In this case, the NET address of R1 is 49.0133.532b.ca14.6915.21311.F40F.1B3a.ba10.00, so the NET address of R3 must be 49.0133.532b.ca14.6915.21311.F40F.1B4a.bb87.00.