2.1 Implement IS-IS (IPv4 and IPv6) 350-501 Practice Questions (Page 5)

Questions 21–25

1. 21foundation · easy

   How do IS-IS metrics propagate across the network?

   • AMetrics are only advertised to directly connected neighbors and not beyond
   • BEach router adds its own interface metric to the metric advertised by the previous router
   • CMetrics are included in LSPs, and each router calculates the total path cost using SPF
   • DMetrics are reset to zero at each router to prevent loops
   Reveal Solution Discussion Select an answer first
2. 22application · medium

   A network engineer is configuring IS-IS on a router that will be used in a single-topology IPv4/IPv6 network. The engineer wants to ensure that the router advertises both IPv4 and IPv6 prefixes. Which configuration is required?

   • AConfigure a separate NET for IPv6.
   • BConfigure wide metrics on all interfaces.
   • CEnable the IPv6 address family under the IS-IS process and configure IPv6 addresses on interfaces.
   • DSet the overload bit on the router.
   Reveal Solution Discussion Select an answer first
4. 23foundation · easy

   What role does the SPF algorithm play in IS-IS route advertisement?

   • AIt floods LSPs to all routers in the network to ensure they have the same database
   • BIt establishes adjacencies with neighboring routers by exchanging Hello PDUs
   • CIt assigns metric values to each interface based on bandwidth and delay
   • DIt selects the best path to each destination by computing the shortest path tree from the link-state database
   Reveal Solution Discussion Select an answer first
5. 24application · medium

   A service provider is designing a new IS-IS network. The network will have three areas: 49.0001, 49.0002, and 49.0003. The engineer wants to ensure that routers in area 49.0001 can communicate with routers in area 49.0002 and 49.0003. The design must minimize the number of Level 2 adjacencies. Which NET configuration is appropriate for the border routers?

   • AUse a NET with a zero area ID on all border routers to enable Level 2 only.
   • BUse a single system ID for all border routers to simplify the NET.
   • CUse the same area ID on all border routers, such as 49.0001, and rely on Level 2 routing.
   • DUse different area IDs on border routers, such as 49.0001, 49.0002, and 49.0003, and configure them as Level 1/Level 2.
   Reveal Solution Discussion Select an answer first
6. 25application · medium

   A network engineer is troubleshooting an IS-IS adjacency between two routers. Both routers are configured for single-topology IS-IS with IPv4 and IPv6. The adjacency is up, but IPv6 routes are not being exchanged. The engineer checks the IS-IS database and sees that the IPv4 reachability TLVs are present, but the IPv6 reachability TLVs are missing. What is the most likely cause?

   • AThe system IDs are not unique.
   • BThe interfaces are not configured with an IPv6 address.
   • CThe routers are using different metric styles.
   • DThe IPv6 address family is not enabled under the IS-IS process on one or both routers.
   Reveal Solution Discussion Select an answer first