Nokia IS-IS Routing Protocol v1.0
Question 1
Routers R1 through R4 in the diagram have established IS-IS adjacencies. Router R1 is L1/L2 and is the DIS of its two broadcast interfaces. How many LSPs will it generate?
- A. 2
- B. 3
- C. 4
- D. 5
Answer : B
Question 2
Examine the physical topology of the IS-IS network, the metrics of the links and the levels of the routers. All routers have their system interfaces included in IS-IS. Which of the following statements describes the route-table entry that router R4 will use to reach the system IP address of router R6?
- A. Router R4 will have a route to router R6’s system IP address with router R2 as the next-hop.
- B. Router R4 will have a default route with router R2 as the next-hop.
- C. Router R4 will have a default route with router R3 as the next-hop.
- D. Router R4 will not have a matching entry in its routing table for router R6’s system IP address.
Answer : A
Question 3
An IS-IS router receives a CSNP that references an older LSP than the one in its local database. What action is taken?
- A. The router sends a copy of the referenced LSP from its database to its neighbor.
- B. The router sends a CSNP to its neighbor describing the newer LSPs in its database.
- C. The router updates its database with the new sequence number and floods a copy of the LSP to its other neighbors.
- D. The router sends a PSNP to its neighbor to request a copy of the LSP.
Answer : A
Question 4
There are several differences between IS-IS Hello packets used on broadcast interfaces and on point-to-point interfaces.
Which of the following statements is FALSE?
- A. On broadcast interfaces there are different Hello packet types for level-1 and level-2 adjacencies, whereas on point-to-point interfaces there is a single Hello packet type.
- B. The multicast MAC addresses to which the Hello messages are sent are different on broadcast interfaces and on point-to-point interfaces.
- C. The neighbors are identified using their interface MAC addresses on broadcast Hello messages and using their system IDs on point-to-point Hello messages.
- D. Broadcast Hello messages identify the elected designed IS (DIS) and point-to-point Hello messages do not.
Answer : C
Question 5
A new router is added to a broadcast network. What does IS-IS use as the tiebreaker for selecting the DIS if the priorities are the same?
- A. The router with the highest system ID.
- B. The Hello packet with the highest sequence number.
- C. The existing DIS remains the DIS.
- D. The router with the highest interface MAC address.
Answer : A
Question 6
Consider the exhibit.
All routers are running IS-IS with IPv6 support enabled. Based on the topology shown, and the route tables of routers R3 and R4, which of the following statements is TRUE?
- A. There is no route leaking configured on router R1 or router R2.
- B. Route leaking is configured on router R1 but not on router R2.
- C. Route leaking is configured on router R2 but not on router R1.
- D. Route leaking is configured on both routers R1 and R2.
Answer : D
Question 7
Consider the exhibit.
All routers are running IS-IS with IPv6 support enabled. Based on the topology shown, and the route tables of routers R3 and R4, which of the following statements is TRUE?
- A. There is no route leaking configured on router R1 or router R2.
- B. Route leaking is configured on router R1 but not on router R2.
- C. Route leaking is configured on router R2 but not on router R1.
- D. Route leaking is configured on both routers R1 and R2.
Answer : D
Question 8
In the IS-IS network shown, router R1 has been configured to summarize subnetworks 20.20.1.0/24 and 20.20.2.0/24 as 20.20.0.0/16. Which routers’ routing tables will be reduced, compared to their routing tables before the summarization?
- A. Router R1
- B. Router R2
- C. Routers R1 and R2
- D. Routers R2 and R4
Answer : B
Question 9
When using IS-IS in native mode for routing in a dual-stack IPv4/IPv6 environment, which of the following statements is FALSE?
- A. All links are assumed to be IPv4- and IPv6-capable.
- B. The same topology information is used to calculate the shortest path tree for both IPv4 and IPv6.
- C. In a multi-area environment, the SPF algorithm needs to be run four times on each L1/L2 router.
- D. It may lead to traffic black-holing if not properly designed.
Answer : C
Question 10
A series of actions are triggered on a router as a result of enabling both loopfree-alternate for a link-state routing protocol and ip-fast-reroute. Which of the following is NOT one of those actions?
- A. Calculating the shortest-path next hop for each known IP prefix.
- B. Calculating a backup next hop for each known IP prefix, if it exists, that would not create a routing loop if used without informing other routers.
- C. Installing two entries in the FIB for IP prefixes, one active and one in standby mode.
- D. Enabling the router to locally repair the active path to an IP prefix in case of failure.
Answer : A
Question 11
What is the purpose of the preference value that the Routing Table Manager (RTM) uses?
- A. To select among routes with different next hops.
- B. To select among routes with different end-to-end costs.
- C. To select among routes learned from different routing protocols.
- D. To select among routes with different prefix lengths.
Answer : C
Question 12
All routers in the diagram are running an interior gateway protocol (IGP) and have been configured with an ECMP value of 4. Router R4 advertises the prefix 192.168.3.0/24 using the IGP. Assuming all links have the same cost, how many entries for prefix 192.168.3.0/24 will be in router R5’s routing table?
- A. 1
- B. 2
- C. 3
- D. 4
Answer : B
Question 13
Which of the following definitions best describes route filtering?
- A. It is the process of deciding at line-rate speed which packets will be dropped and which ones will be forwarded.
- B. It is the process of redirecting packets to be processed by an intermediate network function before allowing them to go to their intended final destination.
- C. It is the process of passing routing information from one routing domain to another, which usually means from one routing protocol to another.
- D. It is the process of controlling which route advertisements received from routing peers are accepted and/or deciding which locally known prefixes are advertised to routing peers.
Answer : D
Question 14
Which component of the Nokia 7750 SR is in charge of supporting dynamic routing protocols and populating the routing table?
- A. Input/Output Module (IOM)
- B. Media Dependent Adapter (MDA)
- C. Control Processing Module (CPM)
- D. Switch Fabric (SF)
Answer : C
Question 15
An IP address is being used as an anycast address. Which of the following statements best describes the forwarding of an IP packet with that address as its destination?
- A. It is sent to all nodes on the local subnetwork
- B. It is forwarded towards all nodes that have joined the anycast group.
- C. It is forwarded towards the nearest node that is assigned the anycast address.
- D. It is forwarded towards all nodes that are assigned the anycast address.
Answer : C