Nokia 4A0-112 Dumps Questions Answers

From the output, we can see that theusagecolumn indicates whether a router is operating as an L1 or L2 router:

RoutersR1andR2have a usage ofL2, meaning they are L2 routers.

RoutersR3andR4have a usage ofL1, meaning they are L1 routers.

TheL1/L2designations refer to whether the routers participate in both Level 1 and Level 2 of IS-IS:

L1 routersonly communicate within their own area.

L2 routerscommunicate between areas.

In this case,R1andR2are L2 routers, andR3andR4are L1 routers.

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.

Router R1 is configured as L1/L2, meaning it is part of both Level 1 and Level 2 IS-IS routing areas. This means R1 will generate two types of LSPs:

Level 1 LSP (for the local area 49.0001) to advertise its local topology to other Level 1 routers.

Level 2 LSP (for the backbone area 49.0002) to advertise the global network topology to Level 2 routers.

R1 also has two broadcast interfaces, and as the Designated Intermediate System (DIS) on these interfaces, it will generate an LSP for each interface (one per broadcast link).

This results in three total LSPs:

A Level 1 LSP for the local area (49.0001).

A Level 2 LSP for the backbone area (49.0002).

An LSP for each of the two broadcast interfaces, which may include interface-related topology information.