3-5: Troubleshoot OSPF Flashcards Preview

CISA-1220 Routing > 3-5: Troubleshoot OSPF > Flashcards

Flashcards in 3-5: Troubleshoot OSPF Deck (50):
1

What command would set the hello-interval to 10 seconds?

ip ospf hello-interval 10

2

DRothers only listen on what IPv6 address?

FF02::6

3

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?

The subnet masks on the two connected serial interfaces do not match.

3

DRs and BDRs listen to what IPv6 address (apart from the address used by DRothers)

FF02::5

3

Dead intervals are auto set to _ times the Hello.

4

3

When convergence has occured, the router is in what state?

Full

4

If priorities are equal (default 1), the router with the highest what wins.

Router ID

5

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?

Issue the clear ip ospf process privileged mode command.

6

What is the first OSPF election criterion for the DR and BDR election process?

The highest interface priority

7

When no OSPF hellos are recieved, the router is most likely in what OSPF state?

Down

8

By default, the router with the highest what is elected as the DR.

Interface priority.

9

DRs and BDRs listen to what IPv4 address (apart from the address used by DRothers)

224.0.0.5

10

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?

  1. show ip ospf neighbor
  2. show ip ospf interface

11

Why do OSPF serial interfaces usually require manual bandwidth configuration?

OSPF uses the bandwidth value to compute routes for its routing table.

12

When OSPFv2 neighbors are establishing adjacencies, in which state do they elect a DR and BDR router?

Two-Way state

13

What is the fourth OSPF election criterion for the DR and BDR election process?

The highest active IPv4 interface address

15

DR/BDR elections only take place on what type of networks?

multi-access

16

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?

The timer intervals of R1 and R2 do not match.

17

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

show ipv6 route

18

Which two pieces of information are used by the OSPF MD5 algorithm to generate a signature?

  1. secret key
  2. OSPF message

18

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

19

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?

This route is a propagated default route.

21

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?

  1. No ipv6 ospf dead-interval
  2. No ipv6 ospf hello-interval

22

What three conclusions can be drawn from the displayed output?

  1. The DR can be reached through the GigabitEthernet 0/0 interface.
  2. There have been 9 seconds since the last hello packet sent.
  3. The router ID values were not the criteria used to select the DR and the BDR.

23

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?

The R1 dead timer expires between hello packets from R2.

25

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?

No router ID has been configured.

26

When you connect distant OSPF areas to the backbone you use what OSPF Network type?

Virtual Links

26

The three types of OSPF authentication are?

  1. Null
  2. Plaintext
  3. MD5

27

What state is OSPF in when LSRs and LSUs are used to gain additional route information?

Loading State

27

What kind of OSPF authentication has been configured on this interface?

MD5

28

What state is OSPF in when a Master / Slave relationship has been negotiated?

ExStart State

30

These two routers are configured to run OSPFv3 but they are not forming a neighbor adjacency. What is the cause of the problem?

The routers are configured with the same router ID.

31

Frame Relays are what OSPF Network Type?

NBMA

32

DRothers only listen on what IPv4 address?

224.0.0.6

34

WAN Links are what type of OSPF Network Type?

Point-to-Point

36

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 60 seconds.

37

Ethernet is what OSPF Network type?

Broadcast Multi-access

38

What command would set the dead-interval to 10 seconds?

ip ospf dead-interval 10

39

A hub-and-spoke topology over NBMA is what type of OSPF Network?

Point-to-multipoint

40

Why is MD5 authentication more secure than simple authentication for OSPF updates?

MD5 does not send the password to the neighbor router.

41

What is the third OSPF election criterion for the DR and BDR election process?

The highest loopback IPv4 address

42

A network engineer is troubleshooting OSPFv2 routing issues on two connected routers. Which two requirements to form an adjacency need to be verified?

  1. Verify that the interfaces that connect the two routers are in the same area.
  2. Verify that the interfaces that connect the two routers are in the same subnet.

43

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?

All of the routers have an OSPFv3 interface priority of 0.

44

What is the second OSPF election criterion for the DR and BDR election process?

The highest manually configured router ID

45

What state is OSPF in when all routers have been converged?

Full State

46

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 interface serial 0/0/0

47

What command will produce this output?

show ip ospf neighbor

48

What command will produce this output?

show ip ospf interface

49

What command will produce this output?

show ip ospf

50

What command will produce this output?

show ip protocols