4A0-112 Practice Exam Questions with Answers Nokia IS-IS Routing Protocol Certification

Router R4 is in Area 49.0001 and R6 is in Area 49.0002. Both routers are Level 2 (L2), meaning that they can communicate across areas using Level 2 IS-IS routing.

Since R2 is the L1/L2 router that connects both Area 49.0001 and Area 49.0002, it will be the next-hop for router R4 to reach R6’s system IP address.

The IS-IS protocol will ensure that R4 will have a route to R6’s system IP address via R2 as the next-hop.

Based on theIPv6 route tableoutput forR3andR4, we can see that the routers have remote routes listed as"Remote ISIS", indicating that the route is being advertised from a different area (area 49.01 or 49.02). This is a sign ofroute leaking, where routes from one area are being shared across areas.

TheroutesfromR3(level-1 router) are being advertised toR4(level-1 router), and vice versa, withISISas the protocol. This implies that there is route leaking configured to allow information to pass between areas.

In IPv6, the Neighbor Discovery Protocol (NDP) replaces the Address Resolution Protocol (ARP) used in IPv4. NDP is responsible for several functions, including resolving IP addresses to MAC addresses (similar to ARP), detecting duplicate IP addresses, and discovering other devices on the network.

Dividing a domain into areas typically does not reduce the number of routers needed to handle traffic. It is more focused on improving scalability, reducing the size of routing tables, and limiting the scope of SPF calculations, but it doesn't inherently reduce the number of routers required.

The Input/Output Module (IOM) is responsible for performing the longest prefix match (LPM) lookup on packets that arrive at the physical interfaces. The IOM performs this function by examining the destination IP address of incoming packets and using the routing table to determine the best match.

The output shows two levels of IS-IS databases: Level 1 (L1) and Level 2 (L2). This indicates that the domain is multi-area, as L1 routers are confined to a single area, while L2 routers can route between different areas. The presence of Level 1/Level 2 (L1/L2) routers also suggests that the domain spans multiple areas.

The LSP (Link-State PDU) entries show L1/L2 ATT attributes, which typically indicate that these routers are capable of routing both within their own area (Level 1) and across areas (Level 2), suggesting a multi-area design.

The IS-IS domain likely includes broadcast interfaces, as indicated by the "ATT" attribute (typically referring to the type of interface) and common IS-IS configuration practices on broadcast networks like Ethernet.

Therouting table manager (RTM)is responsible for selecting the best route when multiple routing protocols provide a route for the same destination prefix. It makes the decision on which route to add to therouting tablebased on the administrative distance, metric, and other criteria.