— Exhibit —
Refer to the Exhibit.
The exhibit displays an IS-IS topology and an IS-IS configuration for R3 and R4. R4 cannot reach
any external destinations or addresses located in Area 49.1111.
How would you ensure that R4 can reach external destinations and addresses located in area
Configure an export policy on R3 that leaks all IS-IS routes from Level 2 to Level 1.
Configure R3’s authentication key to match R4’s authentication key.
Remove the overload statement on R4.
Remove the ignore-attached-bit statement on R4.
7 Comments on “How would you ensure that R4 can reach external destinations and addresses located in area 49.1111?”
I think the topology is wrong, the R3 router should be in area 49.3333. Otherwise is not possible to establish an L1 adjacency between R3 and R4.
Either we can consider there is no L1 adjacencies required because R3 and R4 are from different areas => L2 adjacency
A. change nothing as adjacency to R4 are not L1
C. change nothing : overload doesn’t forbid routing & forwarding, it only push the router with high metric (decreasing priority)
i think so.
Ignore-attached-bit statement is used on Level-1 routers. Adjacency between R3 and R4 is L2.
Why D is correct ?
from l2 routes must leak to l1 so answer should be “A”
D is correct, because if we delete ignore-attached-bit statement, R4 install default route through R3.
but how an L1 adjacency will be formed since:
a. R3 and R4 are in different areas?
b. R4 has L1 authentication and R3 dont?