1,001 CCNA Questions Chapter 9: Dynamic Routing Protocols
Which routing protocol sends the entire routing table to neighboring routers every 30 seconds? (A) OSPF (B) RIP (C) IGRP (D) EIGRP
B. RIP The RIP routing protocol sends routing updates to neighboring routers every 30 seconds.
What version of RIP supports VLSM? (A) RIPv1 (B) RIPv2 (C) RIPv8 (D) RIPv9
B. RIPv2 RIPv2 supports VLSM, which allows the use of different-size subnets.
You are troubleshooting OSPF configuration. What command would you use to verify your configuration? (A) show ospf (B) show ip ospf (C) show interfaces (D) show controllers
B. show ip ospf You can use the show ip ospf command to verify your OSPF configuration.
When troubleshooting OSPF, which of the following commands would you use? (Select two.) (A) show cdp neighbors (B) show ip protocols (C) show mac-address-table (D) show (E) show ip ospf neighbor
B. show ip protocols E. show ip ospf neighbor When troubleshooting OSPF, you can use the show ip protocols command to view which routing protocol is loaded and the show ip ospf neighbor to verify there are neighboring relationships with other routers.
What is the administrative distance of OSPF? (A) 110 (B) 90 (C) 120 (D) 115
A. 110 OSPF has an administrative distance of 110. Routers will use the route with the lowest administrative distance.
When configuring OSPF on your router, you have specified an interface to be part of area 0. What is the area known as? (A) Backbone (B) Branch network (C) Exterior network (D) Internet
A. Backbone Area 0 is known as the backbone of your network. When configuring OSPF, you start with the backbone and then create other areas for remote offices.
Which of the following represents a downfall of distance vector routing protocols over link state? (A) Convergence time (B) Sends updates to all routers (C) Updates are triggered based off events (D) Updates are delivered using unicast communication
A. Convergence time Because distance vector routing protocols only share the routing table with neighboring routers, it could take a long time for all routers to know about changes to the routing table. The time it takes for all routers on a network to know of a change is known as convergence time.
A ______routing protocol is a routing protocol that knows only about how many hops away a network is (A) Distance vector (B) Layer 2 (C) Link state (D) Layer 4
A. Distance vector A distance vector routing protocol only knows how many hops (routers) away a network is; it does not know if a link is available or how much bandwidth the link has.
Which of the following protocols are link state routing protocols? (Select all that apply.) (A) EIGRP (B) RIP (C) IGRP (D) OSPF
A. EIGRP D. OSPF OSPF and EIGRP are examples of link state routing protocols. OSPF is an open standard link state protocol, while EIGRP is a Cisco protocol that uses link state.
Which of the following would be used as the OSPF router ID if all were configured? (A) Highest IP address assigned to a loopback interface (B) Highest IP address assigned to a physical interface (C) Lowest IP address assigned to a loopback interface (D) Lowest IP address assigned to a physical interface
A. Highest IP address assigned to a loopback interface With OSPF, the router ID is chosen by the highest IP address used by a loopback interface. If there are no loopback interfaces, then the router ID will be that of the highest IP address of the physical interfaces.
Which of the following are true statements about RIPv2? (Select three.) (A) It is a classless routing protocol (B) Maximum hop count of 15 (C) Sends updates with broadcast (D) RIPv2 supports authentication (E) Has a high administrative distance than RIPv1
A. It is a classless routing protocol B. Maximum hop count of 15 D. RIPv2 supports authentication RIPv2 is a classless routing protocol that is limited to 15 hops and also supports authentication. This is different than RIPv1, which is a classful routing protocol and does not support authentication.
Which of the following is true regarding link state routing protocols? (Select two.) (A) Routers share routing table information with all other routers on the network (B) Routers share routing table information with neighboring routers (C) Updates are only sent every 60 seconds (D) Maintains multiple tables in memory — one for neighboring routers, one to store the entire topology, and final table is the routing table. (E) Sends entire routing table as an update
A. Routers share routing table information with all other routers on the network D. Maintains multiple tables in memory — one for neighboring routers, one to store the entire topology, and final table is the routing table. Link state routing protocols are aware of the entire network topology because there are multiple tables maintained in memory: a topology table, neighboring routers table, and the routing table. The routing table is shared with all other routers on the network.
When looking at the routing table, how do you know which entries have been learned through RIP? (A) The entry with code R (B) The entry with code C (C) The entry with code RIP (D) The entry with code 1
A. The entry with code R RIP entries found in the routing table display with a code of R.
You want to configure your router for OSPF and run it on interfaces that are on the 192.168.1.0 network. Which of the following commands would you use? (A) Use the following: router ospf 1 network 192.168.1.0 0.0.0.255 area 0 (B) Use the following: router ospf 1 network 192.168.1.0 255.0.0.0 area 0 (C) Use the following: router ospf network 192.168.1.0 0.0.0.255 area 0 (D) Use the following: router ospf 1 network 192.168.1.0 255.255.255.255 area 0
A. Use the following: router ospf 1 network 192.168.1.0 0.0.0.255 area 0 In order to configure OSPF as a dynamic routing protocol on your router, you first use the router ospf 1 command to run an OSPF process as process ID 1 (in this example). You then use the network command to specify what interfaces OSPF will run on. The key point is that the network command uses a wildcard mask and not a subnet mask. You also specify the area <ID> for OSPF. Your router will share routing table information to any other OSPF-enabled routers in the same area.
Which of the following is true about RIPng? (A) You need to enable RIPng on each interface. (B) RIPng uses broadcast traffic to share routing information. (C) RIPng is classful. (D) RIPng supports up to 30 hops.
A. You need to enable RIPng on each interface. RIPng is the next generation version of RIP for IPv6 and requires you to enable RIPng on each interface.
(True/False): RIPv1 is an example of a classless routing protocol. (A) True (B) False
B. False RIPv1 is classful, meaning it cannot use variable length subnet masks ( VLSM).
You want to disable sending RIP messages on interface serial 0/1. Which of the following commands would you use? (A) RouterA(config)#passive-interface serial 0/1 (B) RouterA(config-router)#passive-interface serial 0/1 (C) RouterA#passive-interface serial 0/1 (D) RouterA>passive-interface serial 0/1
B. RouterA(config-router)#passive-interface serial 0/1 To disable sending RIP update messages, you can use the passive-interface command at the router prompt.
Your router receives an update for a route from both RIP and OSP (F) Which route will the router add to its routing table? (A) RIP (B) OSPF (C) Neither (D) Both
B. OSPF Because OSPF has a lower administrative distance than RIP, it would be considered more trustworthy and would be added to the routing table of the router. OSPF has an administrative distance of 110, while RIP has an administrative distance of 120.
Which of the following protocols are distance vector routing protocols supported by multiple vendors and not just Cisco? (A) OSPF (B) RIP (C) IGRP (D) EIGRP
B. RIP RIP is an open standard distance vector routing protocol that is supported by many different router manufacturers.
When RIP has multiple routes to a destination with the same hop count, what will it do? (A) RIP uses the one with the administrative distance of 120. (B) RIP will load-balance the links to that destination. (C) RIP uses the second route in the table. (D) RIP uses the first route in the table.
B. RIP will load-balance the links to that destination. When multiple routes to the same destination exist, with RIP, the router will loadbalance the multiple routes.
Which of the following is true of distance vector routing protocols? (Select two.) (A) Routers share routing table with all other routers on the network (B) Routers share routing table with neighboring routers (C) Updates are only sent every 60 seconds (D) Maintains multiple tables in memory — one for neighboring routers, one to store the entire topology, and final table is the routing table. (E) Sends entire routing table as an update
B. Routers share routing table with neighboring routers E. Sends entire routing table as an update Distance vector routing protocols share their routing table with neighboring routers and typically send the entire routing table as an update.
What is the default administrative distance for RIP? (A) 90 (B) 100 (C) 120 (D) 150
C. 120 RIP uses a default administrative distance of 120.
Which routing protocol is limited to 15 hops? (A) OSPF (B) IGRP (C) RIP (D) EIGRP
C. RIP The RIP routing protocol is limited to 15 hops so is therefore typically only used on smaller networks.
Which of the following is true of a distance vector routing protocol? (Select two.) (A) Uses a topology table to determine whom to send updates to (B) Sends periodic updates (C) Updates routing table based on updates received from neighboring routers (D) Sends entire routing table to all routers on the network (E) Uses the shortest path first algorithm to determine best route
B. Sends periodic updates C. Updates routing table based on updates received from neighboring routers Distance vector routing protocols send out periodic updates (based on an interval) and updates the routing table based on routes received from neighboring routers.
What type of OSPF router connects one or more areas to the backbone network? (A) BR (B) IR (C) ASBR (D) ABR
D. ABR An area border router is designed to connect areas together; specifically, it is designed to connect OSPF areas to the backbone area known as area 0.
You need to configure RIPv2 on your router. Which of the following commands would do this? (A) Use the following commands: R1>router rip R1>network 25.0.0.0 R1>network 26.0.0.0 R1>version 2 (B) Use the following commands: R1(config)#router rip R1(config-router)#network 25.0.0.0 R1(config-router)#network 26.0.0.0 R1(config-router)#version 2 (C) Use the following commands: R1(config)#router rip 2 R1(config-router)#network 25.0.0.0 R1(config-router)#network 26.0.0.0 (D) Use the following commands: R1(config)#router rip version 2 R1(config-router)#network 25.0.0.0 R1(config-router)#network 26.0.0.0
B. Use the following commands: R1(config)#router rip R1(config-router)#network 25.0.0.0 R1(config-router)#network 26.0.0.0 R1(config-router)#version 2 In order to configure your router for version 2 of RIP, you must first enter the router rip command in global configuration mode. Once at the router prompt, you then specify the networks to run RIP on and then use the version 2 command to specify you wish to use RIPv2.
You need to configure OSPF on your router. Which of the following most accurately depicts the commands used? (A) Use the following commands: router ospf 1 network 192.168.1.0 255.255.255.0 area 0 (B) Use the following commands: router ospf 1 network 192.168.1.0 0.0.0.255 area 0 (C) Use the following commands: router ospf network 192.168.1.0 0.0.0.255 area 0 (D) Use the following commands: router ospf network 192.168.1.0 0.0.0.255
B. Use the following commands: router ospf 1 network 192.168.1.0 0.0.0.255 area 0 When configuring OSPF, you must first use the router ospf <ID> command in global configuration, where the ID is the process ID you want to assign to the OSPF process. You then specify the network interfaces to run OSPF on by using the network command and the wildcard mask (not the subnet mask) while specifying the area.
When a router receives a routing table update for a route it does not have in its routing table, what does it do? (A) Adds the route to the MAC address table (B) Adds the route to the ARP cache (C) Adds the route to the routing table (D) Adds the route as the GWLR
C. Adds the route to the routing table When a router receives a routing table update for a route it does not have in its routing table, it adds that route to the routing table.
How frequently does RIPv2 send out routing updates? (A) Every 15 seconds (B) Every 180 seconds (C) Every 30 seconds (D) Every 60 seconds
C. Every 30 seconds The RIP routing protocol, whether RIPv1 or RIPv2, sends routing updates out every 30 seconds. RIPv2 does send those updates out as multicast traffic instead of broadcast traffic, as is the case with RIPv1.
Dynamic routing protocols run at what layer of the OSI model? (A) Layer 1 (B) Layer 2 (C) Layer 3 (D) Layer 4
C. Layer 3 Dynamic routing protocols are routing protocols, so therefore run at layer 3.
OSPF is an example of a ____________ routing protocol. (A) Layer 2 (B) Distance vector (C) Link state (D) Layer 4
C. Link state OSPF is an example of a link state routing protocol.
What command enables RIP debugging? (A) rip debug (B) debug rip (C) debug ip rip (D) enable debug
C. debug ip rip You can enable debugging for RIP to view the RIP-related messages, as they are sent and received, to help troubleshoot RIP.
You wish to see how RIP has been configured on the router. What command would you use? (A) RouterA#show ip config (B) RouterA#show protocols (C) RouterA#show rip protocols (D) RouterA#show ip protocols
D. RouterA#show ip protocols To view the current RIP configuration after RIP has been enabled, you can use the show ip protocols command.
What does the term " routing by rumor " refer to? (A) Broadcasting all routes to neighboring routers (B) Broadcasting all routes to all routers (C) Broadcasting static routes to neighboring routers (D) Sharing routes learned from one neighbor to other neighboring routers
D. Sharing routes learned from one neighbor to other neighboring routers Routing protocols such as RIP only shares their routing table with neighboring routers. Once one router shares its routing table with its neighbors, those neighbors will share the routes out to their neighbors, which is how all routers know of all routes on the network (eventually). This is known as routing by rumor.
Your manager is thinking about upgrading from RIPv1 to RIPv2 and asks about the benefit of RIPv2. What would you say? (A) Supports a maximum of 30 hops (B) Sends updates every 90 seconds (C) Is classful (D) Supports VLSM
D. Supports VLSM RIPv2 has a few benefits. It sends routing updates out via multicast traffic (RIPv1 uses broadcast). Also RIPv2 is classless and supports variable length subnet masks ( VLSM).
The Problems You'll Work On In this chapter, you'll review questions concerning the following topics: ✓ Understanding dynamic routing protocols ✓ Configuring RIP and RIPv2 ✓ Grasping the basics of configuring OSPF
What to Watch Out For Don't let common mistakes trip you up; watch for the following when working with these questions: ✓ To display your routing table, use the show ip route command. To view routing protocol details, you use the show ip protocols command. ✓ Distance vector routing protocols send the entire routing table in an update at regular intervals to neighboring routers, while link state routing protocols are aware of the entire network topology and the state of the links. Distance vector routing protocols use the hop count metric, while link state uses the availability of the link and bandwidth. ✓ RIP is an example of a distance vector routing protocol. To enable RIPv1, you use the router rip command to navigate to the router prompt and then enable RIP on each network interface with the network command. If you wish to use RIPv2, you then type the version 2 command at the router prompt. ✓ When troubleshooting RIP, you can turn on RIP debugging with the debug ip rip command. Be sure to turn off all debugging, when you finish troubleshooting, with the no debug all command.
You have three interfaces on the router: one configured for the 27.0.0.0/8, while the other two interfaces are configured with 29.1.0.0/16 and 29.2.0.0/16. If you want to use RIPv2, which of the following represents the least number of commands you would need to use? (A) Use the following commands: RouterA>enable RouterA#config term RouterA(config)#enable rip RouterA(config)#network 27.0.0.0 RouterA(config)#network 29.0.0.0 RouterA(config)#version 2 (B) Use the following commands: RouterA>enable RouterA#config term RouterA(config)#router rip RouterA(config-router)#network 27.0.0.0 RouterA(config-router)#network 29.1.0.0 RouterA(config-router)#network 29.2.0.0 (C) Use the following commands: RouterA>enable RouterA#config term RouterA(config)#router rip RouterA(config-router)#network 27.0.0.0 RouterA(config-router)#network 29.1.0.0 RouterA(config-router)#network 29.2.0.0 RouterA(config-router)#version 2 (D) Use the following commands: RouterA>enable RouterA#config term RouterA(config)#router rip RouterA(config-router)#network 27.0.0.0 RouterA(config-router)#network 29.0.0.0 RouterA(config-router)#version 2
D. Use the following commands: RouterA>enable RouterA#config term RouterA(config)#router rip RouterA(config-router)#network 27.0.0.0 RouterA(config-router)#network 29.0.0.0 RouterA(config-router)#version 2 When specifying the networks for the RIP routing protocol, you need to specify only the classful addresses, even when the address space has been subnetted.
Which of the following commands would you use to change the router ID of an OSPF router? (A) Use the following: Router rip Router-id 8.8.8.8 (B) Use the following: Router config Router-id 8.8.8.8 (C) Use the following: Router ospf 1 Set Router id 8.8.8.8 (D) Use the following: Router ospf 1 Router-id 8.8.8.8
D. Use the following: Router ospf 1 Router-id 8.8.8.8 When using OSPF, you can change the router ID by using the router ospf 1 command to navigate to the OSPF process, and then type router-id <ip_address> to signify the ID you wish to use for this router.
Which of the following commands enables an OSPFv3 process? (A) router ospf 5 (B) ospf 5 (C) ipv6 ospf 5 (D) ipv6 router ospf 5
D. ipv6 router ospf 5 In order to enabled an OSPFv3 process, you use the IPv6 router OSPF 5 command. Note that OSPFv3 is OSPF for the IPv6 protocol.
