Which IS-IS router is equivalent to an ABR in OSPF?
A.
Level 2-3
B.
Level 1-2
C.
Level 2
D.
Level 0
E.
Level 3
F.
Level 1
Explanation:
The operation of IS-IS is similar to that of OSPF. IS-IS allows the routing domain to be
partitioned into areas. IS-IS routing takes place at Level 1 and Level 2 within an autonomous
system.
Area Border Router (ABR):
Routers that have interfaces attached to multiple areas, maintain separate LSDBs for each
area to which they connect, and route traffic destined to or arriving from other areas is called
Area Border Router(ABR).
Level 1–2: These routers learn about paths both within and between areas. They are
equivalent to area border routers (ABRs) in OSPF