CCNA Routing and Switching: Scaling Networks Chapter 5 Exam

D. Issue the clear ip ospf process privileged mode command.

A network administrator has just changed the router ID on a router that is working in an OSPFv2 environment. What should the administrator do to reset the adjacencies and use the new router ID? A. Change the OSPFv2 process ID. B. Change the interface priority. C. Configure the network statements. D. Issue the clear ip ospf process privileged mode command.

B. The dead interval will now be 60 seconds. Cisco IOS automatically modifies the dead interval to four times the hello interval.

A network engineer has manually configured the hello interval to 15 seconds on an interface of a router that is running OSPFv2. By default, how will the dead interval on the interface be affected? A. The dead interval will now be 15 seconds. B. The dead interval will now be 60 seconds. C. The dead interval will now be 30 seconds. D. The dead interval will not change from the default value.

A. Verify that the interfaces that connect the two routers are in the same area. D. Verify that the interfaces that connect the two routers are in the same subnet. The OSPFv2 process ID is local to each router and does not have to be common. Neither interface on the link connecting the two routers can be passive. Both must be participating in the OSPF area. The DR, BDR, and DRother status of the router has no bearing on the adjacency relationship.

A network engineer is troubleshooting OSPFv2 routing issues on two connected routers. Which two requirements to form an adjacency need to be verified? (Choose two.) A. Verify that the interfaces that connect the two routers are in the same area. B. Verify that one of the routers is the DR or BDR and the other router a DRother. C. Verify that one of the interfaces that connects the two routers is active and the other passive. D. Verify that the interfaces that connect the two routers are in the same subnet. E. Verify that both routers are using the same OSPFv2 process ID.

B. The subnet masks on the two connected serial interfaces do not match. The establishment of an OSPF adjacency between connected routers requires each interface of the link to be in the same subnet. This requires each interface to be configured with correct IP addresses and the same subnet mask. Pings across serial links can be successful with correct IP addresses and different subnet masks. Successful pings verify that a clock rate has been set on the DCE interface of the serial link. The OSPFv2 process IDs on each router are local and do not need to match. A DR election does not take place across point-to-point serial links between OSPF routers.

A network engineer is troubleshooting an OSPFv2 network and discovers that two routers connected by a point-to-point WAN serial link are not establishing an adjacency. The OSPF routing process, network commands and area ID are all confirmed as correct, and the interfaces are not passive. Testing shows that the cabling is correct, that the link is up, and pings between the interfaces are successful. What is most likely the problem? A. The OSPFv2 process IDs on each router do not match. B. The subnet masks on the two connected serial interfaces do not match. C. A clock rate has not been set on the DCE interface of the serial link. D. A DR election has not taken place.

A. show ip ospf neighbor D. show ip ospf interface The show ip ospf interface command will display routing table information that is already known. The show running-configuration and show ip protocols commands will display aspects of the OSPF configuration on the router but will not display adjacency state details or timer interval details.

A network engineer is troubleshooting convergence and adjacency issues in an OSPFv2 network and has noted that some expected network route entries are not displayed in the routing table. Which two commands will provide additional information about the state of router adjacencies, timer intervals, and the area ID? (Choose two.) A. show ip ospf neighbor B. show ip protocols C. show ip route ospf D. show ip ospf interface E. show running-configuration

A. no ipv6 ospf hello-interval F. no ipv6 ospf dead-interval

A network engineer suspects that OSPFv3 routers are not forming neighbor adjacencies because there are interface timer mismatches. Which two commands can be issued on the interface of each OSFPv3 router to resolve all timer mismatches? (Choose two.) A. no ipv6 ospf hello-interval B. no ipv6 router ospf 10 C. no ipv6 ospf cost 10 D. ip ospf hello-interval 10 E. ip ospf dead-interval 40 F. no ipv6 ospf dead-interval The no ipv6 ospf hello-interval and no ipv6 ospf dead-interval commands issued on each OSPFv3 interface will reset the intervals to the respective default periods. This ensures that the timers on all routers now match and, providing other appropriate configurations are correct, the routers will form adjacencies. The ip ospf hello-interval 10 and ip ospf dead-interval 40 commands are OPSFv2 commands that are used for IPv4 routing. If the ipv6 ospf hello-interval and ipv6 ospf dead-interval commands are used, then the interval has to be specified in seconds. The parameter default is not valid in these commands.

C. The R1 dead timer expires between hello packets from R2. The dead timer (20 seconds) on R1 expires before the next hello packet from R2 (25 seconds).

Refer to the exhibit. A network administrator has configured the OSPF timers to the values that are shown in the graphic. What is the result of having those manually configured timers? A. The neighbor adjacency has formed. B. R1 automatically adjusts its own timers to match the R2 timers. C. The R1 dead timer expires between hello packets from R2. D. The hello timer on R2 expires every ten seconds.

A. No router ID has been configured. The output of show ipv6 ospf interface fa0/0 shows that OSPFv3 is not enabled on the interface even though the command is in the running configuration. This is because no router ID has been configured on this router. The router ID in OSPFv3 is a 32 bit number, similar to the ID in OSPFv2. If the router ID is not manually specified then an IPv4 address from one of the interfaces is used instead. This router has no IPv4 addresses configured on it so a router ID cannot be automatically chosen. The router-id command must be configured under ipv6 router ospf 1 in order to fix this problem.

Refer to the exhibit. An administrator is trying to configure R1 to run OSPFv3 but the neighbor adjacency is not forming with the router connected to Fa0/0. What is the cause of the problem? A. No router ID has been configured. B. A link-local address has not been configured on interface FastEthernet0/0. C. The OSPF process ID and area values are backwards in the interface configuration. D. FastEthernet0/0 has been configured as a passive interface.

B. All of the routers have an OSPFv3 interface priority of 0. During the election of a designated router (DR), any routers with a priority of 0 are not eligible to be elected. Because all of the routers in this network have an OSPF priority of 0, no DR will be elected. Routers in a multiaccess network form full adjacencies only with the DR and BDR, and only send routing updates to these two routers. In this network all of the routers have only formed 2-way neighbor relationships and will not exchange routing updates.

Refer to the exhibit. Four routers are connected to an Ethernet LAN segment and are configured to run OSPFv3. However, none of the routers are receiving routing updates. What is the cause of the problem? A. The routers are using IPv4 addresses for router IDs. B. All of the routers have an OSPFv3 interface priority of 0. C. The routers are using IPv6 link local addresses to communicate. D. The network type has been set to BROADCAST instead of NBMA.

B. The timer intervals of R1 and R2 do not match.

Refer to the exhibit. R1 and R2 are connected to the same LAN segment and are configured to run OSPFv3. They are not forming a neighbor adjacency. What is the cause of the problem? A. The OSPFv3 process IDs of R1 and R2 are different. B. The timer intervals of R1 and R2 do not match. C. The IPv6 addresses of R1 and R2 are not in the same subnet. D. The priority value of both R1 and R2 is 1.

A. The routers are configured with the same router ID. The routers have both been configured with the router ID 1.1.1.1. Two OSPFv3 routers with the same router ID will not become neighbors. All routers have a priority of 1 configured by default and this does not normally cause a problem. Both routers have elected themselves as the DR because they are not neighbors, but this is not the cause of the problem either. OSPFv3 routers use their link-local IPv6 addresses to form neighbor relationships, so even if the routers did not have global IPv6 addresses on their interfaces, it would not cause this problem.

Refer to the exhibit. These two routers are configured to run OSPFv3 but they are not forming a neighbor adjacency. What is the cause of the problem? A. The routers are configured with the same router ID. B. The routers have the same priority. C. The routers do not have global IPv6 addresses that are configured on the Fa0/0 interfaces. D. The routers have both been elected as the DR.

B. MD5

Refer to the exhibit. What kind of OSPF authentication has been configured on this interface? A. plain text B. MD5 C. null D. simple

C. The router ID values were not the criteria used to select the DR and the BDR. E. The DR can be reached through the GigabitEthernet 0/0 interface. F. There have been 9 seconds since the last hello packet sent. The DR and BDR process of this matter took place on the multiaccess environment connected to the GigabitEthernet 0/0 interface. The interface is using the priority of 0, which is not the default value. There is no way to know if the DR has three neighbors from the output. The router ID on the DR router is 1.1.1.1. This election was held using priority values, or otherwise the DR would be R3. The next hello is going to be sent in 1 second.

Refer to the exhibit. What three conclusions can be drawn from the displayed output? (Choose three.) A. The router ID on the DR router is 3.3.3.3 B. This interface is using the default priority. C. The router ID values were not the criteria used to select the DR and the BDR. D. The BDR has three neighbors. E. The DR can be reached through the GigabitEthernet 0/0 interface. F. There have been 9 seconds since the last hello packet sent.

show ip route

The command __________ can be issued on router R2 to verify the propagation of a static default route from R1 to R2.

show ip ospf neighbor

When IPv4 and OSPFv2 are being used, the command __________ is used to verify that a router has formed an adjacency with its neighboring routers.

B. Two-Way state Down state: No Hello packets are received. Init state: Hello packets received. Two-way state: DR and BDR election. ExStart state: Negotiate master / slave and DBD packet sequence number. Exchange state: Exchange of DBD packets. Loading state: Additional information is sent. Full state: Routers converged.

When OSPFv2 neighbors are establishing adjacencies, in which state do they elect a DR and BDR router? A. Loading state B. Two-Way state C. Init state D. Exchange state

C. This route is a propagated default route.

When checking a routing table, a network technician notices the following entry: O*E2 0.0.0.0/0 [110/1] via 192.168.16.3, 00:20:22, Serial0/0/0 What information can be gathered from this output? A. The route is located two hops away. B. The edge of the OSPF area 0 is the interface that is addressed 192.168.16.3. C. This route is a propagated default route. D. The metric for this route is 110.

B. show ip protocols

Which command is used to verify that OSPF is enabled and also provides a list of the networks that are being advertised by the network?​ A. show ip route ospf B. show ip protocols C. show ip ospf interface D. show ip interface brief

B. show ip ospf interface serial 0/0/0

Which command will a network engineer issue to verify the configured hello and dead timer intervals on a point-to-point WAN link between two routers that are running OSPFv2? A. show ip ospf neighbor B. show ip ospf interface serial 0/0/0 C. show ip ospf interface fastethernet 0/1 D. show ipv6 ospf interface serial 0/0/0

D. secret key B. OSPF message OSPF MD5 authentication takes the contents of each OSPF message and the configured secret key as input to the MD5 hashing algorithm. The algorithm uses this information to create a signature that is sent with the OSPF message so that the neighbor can verify its authenticity.

Which two pieces of information are used by the OSPF MD5 algorithm to generate a signature? (Choose two.) A. router hostname B. OSPF message C. OSPF router ID D. secret key E. interface IP address

A. OSPF uses the bandwidth value to compute routes for its routing table. The OSPF cost metric is computed using the bandwidth values that are assigned to links. Both ends of a serial link need to have matching values. Serial links may default to several different values, and should always be verified before configuration. The bandwidth value that is assigned to a link does not affect actual speed, but does affect convergence.

Why do OSPF serial interfaces usually require manual bandwidth configuration? A. OSPF uses the bandwidth value to compute routes for its routing table. B. Each side of an OSPF serial link should be configured with a unique value. C. Bandwidth value affects the actual speed of the link. D. All serial interfaces default to a value of 1.544 Mb/s.

B. MD5 does not send the password to the neighbor router. MD5 does not send the configured password across the network. MD5 generates a special hash, or signature, that is attached to the messages and sent to the neighbor. This signature is used to validate the neighbor instead of the password. MD5 does not use a username and does not enforce a minimum length on the password. While IPsec tunnels can be used to keep updates secure, they are not used specifically by MD5.

Why is MD5 authentication more secure than simple authentication for OSPF updates? A. MD5 employs IPsec to keep the updates from being intercepted. B. MD5 does not send the password to the neighbor router. C. MD5 requires passwords that are at least 8 characters long. D. MD5 uses both a username and a password to authenticate the neighbor.