JN0-363 Exam Dumps : Service Provider Routing and Switching, Specialist (JNCIS-SP)

The adjacency SID in segment routing is advertised by one router to inform another about the label that should be used to forward traffic to it over a particular link. In this scenario, Router B would advertise an adjacency SID to Router A, which would be usedby Router A to forward traffic to Router B. Based on the exhibit, the adjacency SID that Router B advertises to Router A would be 12.

References:

• Juniper Networks documentation on Segment Routing: Segment Routing Overview

The exhibit shows an aggregate route configuration for the network172.21.0.0/22, which would summarize the specific networks172.21.0.0/24,172.21.1.0/24, and172.21.2.0/24. For an aggregate route to be active, it must have contributing routes in the routing table. If the route is hidden, it usually means there are no contributing routes that are active or the policy applied to the aggregate does not match any of the specific routes.Therefore, the first step in troubleshooting would be to verify that there are indeed active contributing routes for the aggregate to be valid.

References:

• Juniper documentation on routing policies and aggregates: Junos OS Routing Policies, Firewall Filters, and Traffic Policers User Guide

In MPLS (Multiprotocol Label Switching) networks, routers use label switching to forward packets. The first router at the edge of the MPLS network (R1) will perform a lookup in the mpls.0 table to determine the label to attach to the packet as it enters the MPLS network. This label informs the next routers in the MPLS network (like R2) on how to forward the packet. Internal MPLS routers, like R2, also perform lookups in their mpls.0 table to determine how to switch the packet toward its destination (label swapping). The inet.3 table is used for resolving next-hop information for labeled routes, but it's the mpls.0 table that is used for label switching decisions.

References:

• Juniper Networks documentation on MPLS: MPLS Applications User Guide for Routing Devices