Routing/Switching Checkpoint Exam: OSPF Concepts and Configuration Exam

An administrator is configuring single-area OSPF on a router. One of the networks that must be advertised is 198.19.0.0 255.255.252.0. What wildcard mask would the administrator use in the OSPF network statement? - 0.0.3.255 - 0.0.31.255 - 0.0.0.255 - 0.0.63.255

- 0.0.3.255

By default, what is the OSPF cost for any link with a bandwidth of 100 Mb/s or greater? - 1 - 100 - 100000000 - 10000

- 1

Refer to the exhibit. If no router ID was manually configured, what would router Branch1 use as its OSPF router ID? - 209.165.201.1 - 192.168.1.100 - 10.1.0.1 - 10.0.0.1

- 192.168.1.100

Refer to the exhibit. What is the OSPF cost to reach the router A LAN 172.16.1.0/24 from B? - 65 - 74 - 782 - 128

- 65

Open the PT Activity. Perform the tasks in the activity instructions and then answer the question. Which task has to be performed on Router 1 for it to establish an OSPF adjacency with Router 2? - Remove the passive interface command from interface FastEthernet 0/0. - Add the network 10.0.1.0 0.0.0.255 area 0 command to the OSPF process. - Change the subnet mask of interface FastEthernet 0/0 to 255.255.255.0. - Issue the clear ip ospf process command.

- Change the subnet mask of interface FastEthernet 0/0 to 255.255.255.0.

After modifying the router ID on an OSPF router, what is the preferred method to make the new router ID effective? - HQ# resume - HQ# copy running-config startup-config - HQ# clear ip route * - HQ# clear ip ospf process

- HQ# clear ip ospf process

Refer to the exhibit. Suppose that routers B, C, and D have a default priority, and router A has a priority 0. Which conclusion can be drawn from the DR/BDR election process?​ - If the priority of router C is changed to 255, then it will become the DR. - Router A will become the DR and router D will become the BDR.​ - If a new router with a higher priority is added to this network, it will become the DR. - If the DR fails, the new DR will be router B.

- If the DR fails, the new DR will be router B.

Refer to the exhibit. A network administrator has configured OSPFv2 on the two Cisco routers but PC1 is unable to connect to PC2. What is the most likely problem? - Interface Fa0/0 is configured as a passive-interface on router R2. - Interface s0/0 has not been activated for OSPFv2 on router R2. - Interface Fa0/0 has not been activated for OSPFv2 on router R2. - Interface S0/0 is configured as a passive-interface on router R2.

- Interface Fa0/0 has not been activated for OSPFv2 on router R2.

In an OSPFv2 configuration, what is the effect of entering the command network 192.168.1.1 0.0.0.0 area 0? - It tells the router which interface to turn on for the OSPF routing process. - It changes the router ID of the router to 192.168.1.1. - It enables OSPF on all interfaces on the router. - It allows all 192.168.1.0 networks to be advertised.

- It tells the router which interface to turn on for the OSPF routing process.

Refer to the exhibit. On which router or routers would a default route be statically configured in a corporate environment that uses single area OSPF as the routing protocol? - ISP, R0-A, R0-B, and R0-C - ISP - R0-B and R0-C - R0-A - ISP and R0-A - R0-A, R0-B, and R0-C

- R0-A

Refer to the exhibit. Which command did an administrator issue to produce this output? - R1# show ip ospf - R1# show ip ospf interface serial0/0/1 - R1# show ip ospf neighbor - R1# show ip route ospf

- R1# show ip ospf interface serial0/0/1

Refer to the exhibit. If the switch reboots and all routers have to re-establish OSPF adjacencies, which routers will become the new DR and BDR? - Router R4 will become the DR and router R3 will become the BDR. - Router R4 will become the DR and router R1 will become the BDR. - Router R2 will become the DR and router R3 will become the BDR. - Router R1 will become the DR and router R2 will become the BDR.

- Router R4 will become the DR and router R1 will become the BDR.

Match the description to the term. Categories: a) This is the algorithm used by OSPF. b) This is where you can find the topology table. c) All the routers are in the backbone area. d) This is where the details of the neighboring routers can be found. Options: - Shortest Path First - Link-state database - Single-area OSPF - Adjacency database

- Shortest Path First a) This is the algorithm used by OSPF. - Link-state database b) This is where you can find the topology table. - Single-area OSPF c) All the routers are in the backbone area. - Adjacency database d) This is where the details of the neighboring routers can be found.

Refer to the exhibit. Which three statements describe the results of the OSPF election process of the topology that is shown in the exhibit? (Choose three.) - The R4 router ID is 172.16.1.1. - R2 will be elected DR. - R3 will be elected BDR. - The R4 FastEthernet 0/0 priority is 128. - R1 will be elected BDR. - The router ID on R2 is the loopback interface.

- The R4 router ID is 172.16.1.1. - R2 will be elected DR. - R3 will be elected BDR.

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? - The dead interval will now be 15 seconds. - The dead interval will now be 30 seconds. - The dead interval will now be 60 seconds. - The dead interval will not change from the default value.

- The dead interval will now be 60 seconds.

What is a benefit of multiarea OSPF routing? - Topology changes in one area do not cause SPF recalculations in other areas. - Routers in all areas share the same link-state database and have a complete picture of the entire network. - Automatic route summarization occurs by default between areas. - A backbone area is not required.

- Topology changes in one area do not cause SPF recalculations in other areas.

Which three OSPF states are involved when two routers are forming an adjacency? (Choose three.) - ExStart - Two-way - Exchange - Loading - Down - Init

- Two-way - Down - Init

Match the OSPF state with the order in which it occurs. Categories: a) third state b) fifth state c) first state d) second state e) seventh state f) sixth state g) fourth state Options: - Two-way state - Exstart state - Loading state - Exchange state - Full state - Down state - Init state

- Two-way state a) third state - Exstart state g) fourth state - Loading state f) sixth state - Exchange state b) fifth state - Full state e) seventh state - Down state c) first state - Init state d) second state

What is the format of the router ID on an OSPF-enabled router? - a unique phrase with no more than 16 characters - a character string with no space - a 32-bit number formatted like an IPv4 address - an 8-bit number with a decimal value between 0 and 255 - a unique router host name that is configured on the router

- a 32-bit number formatted like an IPv4 address

Match each OSPF packet type to how it is used by a router. Categories: a) hello packet b) link-state update packet c) link-state request packet d) database description packet Options: - advertise new information - establish and maintain adjacencies - query another router for additional information - compare local topology to that sent by another router

- advertise new information b) link-state update packet - establish and maintain adjacencies a) hello packet - query another router for additional information c) link-state request packet - compare local topology to that sent by another router d) database description packet

What will an OSPF router prefer to use first as a router ID? - the highest active interface that participates in the routing process because of a specifically configured network statement - a loopback interface that is configured with the highest IP address on the router - any IP address that is configured using the router-id command - the highest active interface IP that is configured on the router

- any IP address that is configured using the router-id command

When an OSPF network is converged and no network topology change has been detected by a router, how often will LSU packets be sent to neighboring routers? - every 30 minutes - every 10 minutes - every 5 minutes - every 60 minutes

- every 30 minutes

Which step does an OSPF-enabled router take immediately after establishing an adjacency with another router? - builds the topology table - executes the SPF algorithm - chooses the best path - exchanges link-state advertisements

- exchanges link-state advertisements

Which step in the link-state routing process is described by a router flooding link-state and cost information about each directly connected link? - selecting the router ID - building the topology table - exchanging link-state advertisements - injecting the default route

- exchanging link-state advertisements

What indicates to a link-state router that a neighbor is unreachable? - if the router no longer receives routing updates - if the router receives an update with a hop count of 16 - if the router no longer receives hello packets - if the router receives an LSP with previously learned information

- if the router no longer receives hello packets

An OSPF router has three directly connected networks; 172.16.0.0/16, 172.16.1.0/16, and 172.16.2.0/16. Which OSPF network command would advertise only the 172.16.1.0 network to neighbors? - router(config-router)# network 172.16.1.0 0.0.0.0 area 0 - router(config-router)# network 172.16.1.0 0.0.255.255 area 0 - router(config-router)# network 172.16.0.0 0.0.15.255 area 0 - router(config-router)# network 172.16.1.0 255.255.255.0 area 0

- router(config-router)# network 172.16.1.0 0.0.255.255 area 0 NetAcad said it was wrong

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? - show ip ospf neighbor - show ipv6 ospf interface serial 0/0/0 - show ip ospf interface serial 0/0/0 - show ip ospf interface fastethernet 0/1

- show ip ospf interface serial 0/0/0

What command would be used to determine if a routing protocol-initiated relationship had been made with an adjacent router? - ping - show ip protocols - show ip interface brief - show ip ospf neighbor

- show ip ospf neighbor

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?​ - show ip protocols - show ip interface brief - show ip ospf interface - show ip route ospf

- show ip protocols

A network technician issues the following commands when configuring a router: R1(config)# router ospf 11 R1(config-router)# network 10.10.10.0 0.0.0.255 area 0 What does the number 11 represent? - the administrative distance that is manually assigned to R1 - the cost of the link to R1 - the OSPF process ID on R1 - the area number where R1 is located - the autonomous system number to which R1 belongs

- the OSPF process ID on R1

What is used to facilitate hierarchical routing in OSPF? - the use of multiple areas - autosummarization - the election of designated routers - frequent SPF calculations

- the use of multiple areas

What is the reason for a network engineer to alter the default reference bandwidth parameter when configuring OSPF? - to force that specific link to be used in the destination route - to increase the speed of the link - to enable the link for OSPF routing - to more accurately reflect the cost of links greater than 100 Mb/s

- to more accurately reflect the cost of links greater than 100 Mb/s

In an OSPF network when are DR and BDR elections required? - when the routers are interconnected over a common Ethernet network - when the two adjacent neighbors are in two different networks - when the two adjacent neighbors are interconnected over a point-to-point link - when all the routers in an OSPF area cannot form adjacencies

- when the routers are interconnected over a common Ethernet network