4A0-112 Exam Dumps : Nokia IS-IS Routing Protocol

ARP for IPv4 and Neighbor Discovery Protocol (NDP) for IPv6 are both used to map a device's IP address to its MAC address. This is essential for communication within a local network.

ARP is used in IPv4 networks, and NDP performs a similar function in IPv6 networks, ensuring devices can communicate effectively on the same network segment.

In the configuration on router R1, the static route is defined with the next-hop IP address of139.120.121.1.

However, the next-hop IP address139.120.121.1does not belong to the same subnet as the directly connected interface on R1, which is172.31.1.1/30. For the static route to work properly, the next-hop IP address must be reachable via a directly connected interface, meaning it must be within the same subnet.

Therefore, this mismatch in subnet adjacency is likely causing the failure to reach the destination (139.120.121.2).

From the route tables ofR3andR4, we can see thatremote routesare present, withR3andR4both having routes referencing routers in different areas (Area 49.01 and 49.02). These remote routes are characteristic ofroute leaking, which is the process of sharing routes between different IS-IS areas.

R3has routes forR1,R2, andR4, which are in Area 49.01, suggesting thatR1 and R2have advertised their routes toR3, possibly due toroute leaking.

R4has similar routes forR2andR3, indicating thatR2might have advertised its routes toR4.

This sharing of routes between areas is indicative ofroute leakingbeing configured on bothR1andR2, allowing these routes to be shared across the areas.