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CCNP ENCOR > Ch 8: OSPF > Flashcards

Ch 8: OSPF Flashcards

1
Q

OSPF uses the protocol number ___________ for its inter-router communication.

a. 87
b. 88
c. 89
d. 90

A

C. OSPF uses protocol number 89.

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2
Q

OSPF uses ___________ packet types for inter-router communication.

a. three
b. four
c. five
d. six
e. seven

A

C. OSPFv2 use five packet types for communication:

  1. hello
  2. database description
  3. link state request
  4. link state update
  5. link state acknowledgment.
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3
Q

What destination addresses does OSPF use, when feasible? (Choose two.)

  1. IP address 224.0.0.5
  2. IP address 224.0.0.10
  3. IP address 224.0.0.8
  4. MAC address 01:00:5E:00:00:05
  5. MAC address 01:00:5E:00:00:0A
A

1 and 4. OSPF uses the multicast IP address 224.0.0.5 or the MAC address 01:00:5e:00:00:05 for the AllSPFRouters group.

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4
Q

T/F: OSPF is only enabled on a router interface by using the command network ip-address wildcard-mask area area-id under the OSPF router process.

A

False. OSPF can also be enabled with the interface command ip ospf process-id area area-id.

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5
Q

T/F: The OSPF process ID must match for routers to establish a neighbor adjacency.

A

False. The OSPF process ID is locally significant and is not required to match for neighbor adjacency.

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6
Q

T/F: A default route advertised with the command default information-originate in OSPF will always appear as an OSPF inter-area route.

A

False.

An OSPF advertised default route always appears as an external route.

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7
Q

T/F: The router with the highest IP address is the designated router when using a serial point-to-point link.

A

False.

Serial point-to-point links are automatically set as an OSPF point-to-point network type, which does not have a designated router.

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8
Q

OSPF automatically assigns a link cost to an interface based on a reference bandwidth of ___________.

  1. 100 Mbps
  2. 1 Gbps
  3. 10 Gbps
  4. 40 Gbps
A

1.

IOS XE uses a reference bandwidth of 100 Mbps for dynamic metric assignment to an interface.

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9
Q

What command is configured to prevent a router from becoming the designated router for a network segment?

  1. The interface command ip ospf priority 0
  2. The interface command ip ospf priority 255
  3. The command dr-disable interface-id under the OSPF process
  4. The command passive interface interface-id under the OSPF process
  5. The command dr-priority interface-id 255 under the OSPF process
A

1.

Setting the interface priority to 0 removes the interface from the DR election process.

  • The default priority is 1.
  • You need to use clear ip ospf process-id before this change takes effect.
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10
Q

What is the OSPF advertised network for the loopback interface with IP address 10.123.4.1/30?

a. 10.123.4.1/24
b. 10.123.4.0/30
c. 10.123.4.1/32
d. 10.123.4.0/24

A

C. The loopback address is classified as an OSPF loopback interface type, which is always advertised as a /32 address, regardless of the subnet mask.

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11
Q

What is contained in an LSA?

A

OSPF sends to neighboring routers link-state advertisements (LSAs) that contain the link state and link metric.

The received LSAs are stored in a local database called the link-state database (LSDB), and they are flooded throughout the OSPF routing domain, just as the advertising router advertised them. All OSPF routers maintain a synchronized identical copy of the LSDB for the same area.

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12
Q

T/F: Each OSPF router sees itself as the root or top of the SPF tree (SPT), and the SPT contains all network destinations within the OSPF domain.

A

Each router sees itself as the root or top of the SPF tree (SPT), and the SPT contains all network destinations within the OSPF domain.

The SPT differs for each OSPF router, but the LSDB used to calculate the SPT is identical for all OSPF routers.

Figure 8-1 shows a simple OSPF topology and the SPT from R1’s and R4’s perspective. Notice that the local router’s perspective will always be the root (top of the tree). There is a difference in connectivity to the 10.3.3.0/24 network from R1’s SPT and R4’s SPT. From R1’s perspective, the serial link between R3 and R4 is missing; from R4’s perspective, the Ethernet link between R1 and R3 is missing.

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13
Q

T/F: OSPF provides scalability for the routing table by using multiple OSPF areas within the routing domain.

A

True.

Each OSPF area provides a collection of connected networks and hosts that are grouped together. OSPF uses a two-tier hierarchical architecture, where Area 0 is a special area known as the backbone, to which all other areas must connect. In other words, Area 0 provides transit connectivity between nonbackbone areas. Nonbackbone areas advertise routes into the backbone, and the backbone then advertises routes into other non- backbone areas.

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14
Q

T/F: When you segment an OSPF routing domain into multiple areas, it is no longer true that all OSPF routers will have identical LSDBs.

A

True.

The exact topology of the area is invisible from outside the area while still providing connectivity to routers outside the area. This means that routers outside the area do not have a complete topological map for that area, which reduces OSPF traffic in that area. When you segment an OSPF routing domain into multiple areas, it is no longer true that all OSPF rout- ers will have identical LSDBs; however, all routers within the same area will have identical area LSDBs.

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15
Q

T/F: A router can run multiple OSPF processes and the process numbers need to match for routers to exchange routes in an area.

A

True and False.

A router can run multiple OSPF processes. Each process maintains its own unique database, and routes learned in one OSPF process are not available to a different OSPF process without redistribution of routes between processes.

The OSPF process numbers are locally significant and do not have to match among routers. Running OSPF process number 1 on one router and running OSPF process number 1234 will still allow the two routers to become neighbors.

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16
Q

T/F: SPF runs directly over IPv4, using its own protocol 88.

A

False.

OSPF runs directly over IPv4, using its own protocol 89, which is reserved for OSPF by the Internet Assigned Numbers Authority (IANA).

EIGRP uses protocol number 88.

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17
Q

What address(es) does OSPF use to communicate amongst routers?

A

OSPF uses multicast where possible to reduce unnecessary traffic. The two OSPF multicast addresses are as follows:

AllSPFRouters: IPv4 address 224.0.0.5 or MAC address 01:00:5E:00:00:05. All routers running OSPF should be able to receive these packets.

AllDRouters: IPv4 address 224.0.0.6 or MAC address 01:00:5E:00:00:06. Communication with designated routers (DRs) uses this address.

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18
Q

How many packet types does OSPF use?

A

5 types.

  1. Hello
  2. Database description (DBD) or (DDP)
  3. Link-state request (LSR)
  4. Link-state update (LSU)
  5. Link-state ack
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19
Q

What is the function of Hello packets in OSPF?

A

These packets are for discovering and maintaining neighbors. Packets are sent out periodically on all OSPF interfaces to discover new neighbors while ensuring that other adjacent neighbors are still online.

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20
Q

What is the function of Database description (DBD) or (DDP) packets in OSPF?

A

These packets are for summarizing database contents. Packets are exchanged when an OSPF adjacency is first being formed. These packets are used to describe the contents of the LSDB.

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21
Q

What is the function of Link-state request (LSR) packets in OSPF?

A

These packets are for database downloads. When a router thinks that part of its LSDB is stale, it may request a portion of a neighbor’s database by using this packet type.

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22
Q

What is the function of Link-state update (LSU) packets in OSPF?

A

These packets are for database updates. This is an explicit LSA for a specific network link and normally is sent in direct response to an LSR.

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23
Q

What is the function of Link-state ack packets in OSPF?

A

These packets are for flooding acknowledgments. These packets are sent in response to the flooding of LSAs, thus making flooding a reliable transport feature.

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24
Q

What address are Hello packets usually sent to in OSPF?

A

OSPF hello packets are responsible for discovering and maintaining neighbors. In most instances, a router sends hello packets to the AllSPFRouters address (224.0.0.5). Table 8-3 lists some of the data contained within an OSPF hello packet.

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25
Q

How many bits is a RID in OSPF?

A

The OSPF router ID (RID) is a 32-bit number that uniquely identifies an OSPF router.

In some OSPF output commands, neighbor ID refers to the RID; the terms are synonymous. The RID must be unique for each OSPF process in an OSPF domain and must be unique between OSPF processes on a router.

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26
Q

What are the 3 options for Auththentication in OSPF?

A

Within the Hello packet exists a field that allows secure communication between OSPF routers to prevent malicious activity called the Authentication option field.

Options are none, clear text, or Message Digest 5 (MD5) authentication.

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27
Q

T/F: The Area ID in OSPF can be written as DDN or base 10.

A

True.

The OSPF area that the OSPF interface belongs to is a 32-bit number that can be written in dotted-decimal format (0.0.1.0) or decimal (256).

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28
Q

T/F: Only the DR maintains a complete neighbor table in OSPF?

A

False.

Each OSPF process maintains a table for adjacent OSPF neighbors and the state of each router. Table 8-4 briefly describes the OSPF neighbor states.

Dogs Attack Individuals To Earn Eating Lovely Food.

29
Q

What is the formula to determine the number of adjacencies that will form with a full mesh OSPF network?

A

The number of edges formula, n(n – 1) / 2, where n represents the number of routers, is used to identify the number of sessions in a full mesh topology.

30
Q

T/F: The DR reduces the number of OSPF adjacencies on a multi-access network segment because routers only form a full OSPF adjacency with the DR and not each other.

A

True.

OSPF overcomes the exponential growth of full mesh adjacendies by creating a pseudonode (virtual router) to manage the adjacency state with all the other routers on that broadcast network segment. A router on the broadcast segment, known as the designated router (DR), assumes the role of the pseudonode.

The DR reduces the number of OSPF adjacencies on a multi-access network segment because routers only form a full OSPF adjacency with the DR and not each other. The DR is responsible for flooding updates to all OSPF routers on that segment as the updates occur. Figure 8-5 demonstrates how using a DR simplifies a four-router topology with only three neighbor adjacencies.

31
Q

T/F: The BDR also forms full OSPF adjacencies with all OSPF routers on a segment to minimize transition time if the DR fails.

A

True.

If the DR were to fail, OSPF would need to form new adjacencies, invoking all new LSAs, and could potentially cause a temporary loss of routes. In the event of DR failure, a backup designated router (BDR) becomes the new DR; then an election occurs to replace the BDR. To minimize transition time, the BDR also forms full OSPF adjacencies with all OSPF routers on that segment.

32
Q

The DR/BDR process distributes LSAs with these 4 steps. Put them in order.

  1. As an OSPF router learns of a new route, it sends the updated LSA to the AllDRouters (224.0.0.6) address, which only the DR and BDR receive and process, as illustrated in step 1 of Figure 8-6.
  2. All OSPF routers (DR, BDR, and DROTHER) on a segment form full OSPF adjacencies with the DR and BDR.
  3. The DR floods the LSA to all the routers on the segment via the AllSPFRouters (224.0.0.5) address, as shown in step 3 of Figure 8-6.
  4. The DR sends a unicast acknowledgment to the router that sent the initial LSA update, as illustrated in step 2 of Figure 8-6.
A

The DR/BDR process distributes LSAs in the following manner:

  1. All OSPF routers (DR, BDR, and DROTHER) on a segment form full OSPF adjacencies with the DR and BDR.
  2. As an OSPF router learns of a new route, it sends the updated LSA to the AllDRouters (224.0.0.6) address, which only the DR and BDR receive and process, as illustrated in step 1 of Figure 8-6.
  3. The DR sends a unicast acknowledgment to the router that sent the initial LSA update, as illustrated in step 2 of Figure 8-6.
  4. The DR floods the LSA to all the routers on the segment via the AllSPFRouters (224.0.0.5) address, as shown in step 3 of Figure 8-6.
33
Q

What is the command to enable an OSPF process on a router?

A

The command router ospf process-id defines and initializes the OSPF process.

The OSPF process ID is locally significant but is generally kept the same for operational consistency.

34
Q

List two ways to enable OSPF on an interface.

A

OSPF is enabled on an interface using two methods.

1. An OSPF network statement:

  • network ip-address wildcard-mask area area-id.
  • The OSPF network statement identifies the interfaces that the OSPF process will use and the area that those interfaces participate in. The network statements match against the primary IPv4 address and netmask associated with an interface.
  • A common misconception is that the network statement advertises the networks into OSPF; in reality, though, the network statement is selecting and enabling OSPF on the interface. The interface is then advertised in OSPF through the LSA. The network statement uses a wildcard mask, which allows the configuration to be as specific or vague as necessary.

2. Interface-specific configuration:

  • ip ospf process-id area area-id [secondaries none]
  • This method also adds secondary connected networks to the LSDB unless the secondaries none option is used.
  • This method provides explicit control for enabling OSPF; however, the configuration is not centralized and increases in complexity as the number of interfaces on the routers increases.
  • If a hybrid configuration exists on a router, interface-specific settings take precedence over the network statement with the assignment of the areas.
35
Q

If you do not manually assign the RID to an OSPF router, what will be assigned to be the RID?

A
  1. By default, the RID is dynamically allocated using the highest IP address of any up loopback interfaces.
  2. If there are no up loopback interfaces, the highest IP address of any active up physical interfaces becomes the RID when the OSPF process initializes.
36
Q

When is the RID selected by OSPF and when is it possible to change?

A

The OSPF process selects the RID when the OSPF process initializes, and it does not change until the process restarts. Interface changes (such as addition/removal of IP addresses) on a router are detected when the OSPF process restarts, and the RID changes accordingly.

37
Q

What command will statically assign the RID?

A

The command router-id router-id statically assigns the OSPF RID under the OSPF process.

38
Q

What command will restart an OSPF process?

A

The command clear ip ospf process restarts the OSPF process on a router so that OSPF can use the new RID.

39
Q

What are the OSPF commands to make

  • a specific interface passive?
  • all interfaces passive, globally?
  • to enable an interface to process OSPF packets?
A

The command passive interface-id under the OSPF process makes the interface passive.

The command passive interface default under the OSPF process makes all interfaces passive.

To allow for an interface to process OSPF packets, the command no passive interface-id under the OSPF process is used.

40
Q

What interface command will allow an interface to be added to the LSDB but not allow it to form adjacencies?

A

There is none. This can be done by making an interface passive under OSPF config or globally but not on an interface directly.

NOTE: It is possible to add an interface to OSPF in the interface config, but not make it passive. e.g. ip ospf 1 area 0

The command passive interface-id under the OSPF process makes the interface passive, and the command passive interface default makes all interfaces passive.

Enabling an interface with OSPF is the quickest way to advertise a network segment to other OSPF routers. However, it might be easy for someone to plug in an unauthorized OSPF router on an OSPF-enabled network segment and introduce false routes, thus causing havoc in the network. Making the network interface passive still adds the network segment into the LSDB but prohibits the interface from forming OSPF adjacencies. A passive interface does not send out OSPF hellos and does not process any received OSPF packets.

41
Q

T/F: A passive interface does not send out OSPF hellos and does not process any received OSPF packets.

A

True.

42
Q

Which one of the following list of requirements that must be met for an OSPF neighborship to be formed is not true:

  1. RIDs must be unique between the two devices. They should be unique for the entire OSPF routing domain to prevent errors.
  2. The interfaces must share a common subnet. OSPF uses the interface’s primary IP address when sending out OSPF hellos. The network mask (netmask) in the hello packet is used to extract the network ID of the hello packet.
  3. The MTUs (maximum transmission units) on the interfaces must match. The OSPF protocol does not support fragmentation, so the MTUs on the interfaces should match.
  4. The area ID must match for the segment.
  5. The DR enablement must match for the segment.
  6. OSPF hello and dead timers must match for the segment.
  7. The AS number both the neighbors needs to match.
  8. Authentication type and credentials (if any) must match for the segment.
  9. Area type flags must match for the segment (for example, Stub, NSSA). (These are not discussed in this book.)
A

7 is applicable to EIGRP, not OSPF.

43
Q

T/F: The OSPF protocol support fragmentations, so the MTUs on the interfaces don’t need to match.

A

False.

The OSPF protocol does not support fragmentation, so the MTUs on the interfaces should match.

44
Q

What command would you use to verify that the correct interfaces are running OSPF?

A

The command show ip ospf interface [brief | interface-id] displays the OSPF-enabled interfaces.

It is a good practice to verify that the correct interfaces are running OSPF after making changes to the OSPF configuration.

Example 8-7 displays a snippet of the output from R1. The output lists all the OSPF-enabled interfaces, the IP address associated with each interface, the RID for the DR and BDR (and their associated interface IP addresses for that segment), and the OSPF timers for that interface.

45
Q

What fields are shown with the command show ip ospf interface brief?

A
  • Interface
  • PID
  • Area (The OSPF process ID associated with this interface)
  • IP address/Mask
  • Cost
  • State (The current interface state, which could be DR, BDR, DROTHER, LOOP, or Down)
  • NbrsF = (The number of neighbor OSPF routers for a segment that are fully adjacent)
  • NbrsC = (The number of neighbor OSPF routers for a segment that have been detected and are in a 2-Way state)
46
Q

What is a DROTHER router?

A

The DROTHER is a router on the DR-enabled segment that is not the DR or the BDR; it is simply the other router. DROTHERs do not establish full adjacency with other DROTHERs.

47
Q

What is the command to view the OSPF neighbor table?

A

The command show ip ospf neighbor [detail] provides the OSPF neighbor table. Example 8-9 shows sample output on R1, R2, R3, and R4.

48
Q

What is the command to verify the OSPF routes installed are in the IP routing table? (OSPF routes install into the RIB/Routing Information Base in the control plane.)

A

To verify the OSPF routes are installed in the RIB/ IP routing table, use the command show ip route ospf.

Example 8-10 provides sample output of the OSPF routing table for R1. In the output, where two sets of numbers are in the brackets (for example, [110/2], the first number is the administrative distance (AD), which is 110 by default for OSPF, and the second number is the metric of the path used for that network. The output for R2, R3, and R4 would be similar to the output in Example 8-10.

49
Q

What is the command to advertise a default route into an OSPF domain?

A

OSPF supports advertising the default route into the OSPF domain. The default route is advertised by using the command default-information originate [always] [metric metric- value] [metric-type type-value] underneath the OSPF process.

If a default route does not exist in a routing table, the always optional keyword advertises a default route even if a default route does not exist in the RIB. In addition, the route metric can be changed with the metric metric-value option, and the metric type can be changed with the metric-type type-value option.

50
Q

T/F: Interface cost is an essential component of Dijkstra’s SPF calculation because the shortest path metric is based on the cumulative interface cost (that is, metric) from the router to the destination.

A

True.

Interface cost is an essential component of Dijkstra’s SPF calculation because the shortest path metric is based on the cumulative interface cost (that is, metric) from the router to the destination. OSPF assigns the OSPF link cost (that is, metric) for an interface by using this formula:

Link Cost = (Reference Bandwidth) / (Interface Bandwidth)

The default reference bandwidth is 100 Mbps. Table 8-8 provides the OSPF cost for common network interface types using the default reference bandwidth.

51
Q

What is the OSPF dead interval timer and how does it work?

A

Failure Detection

A secondary function of the OSPF hello packets is to ensure that adjacent OSPF neighbors are still healthy and available. OSPF sends hello packets at set intervals, based on the hello timer.

OSPF uses a second timer called the OSPF dead interval timer, which defaults to four times the hello timer. Upon receipt of a hello packet from a neighboring router, the OSPF dead timer resets to the initial value and then starts to decrement again. If a router does not receive a hello before the OSPF dead interval timer reaches 0, the neighbor state is changed to down.

The OSPF router immediately sends out the appropriate LSA, reflecting the topology change, and the SPF algorithm processes on all routers within the area.

52
Q

What is the range of intervals available for Hello packet frequency?

A

OSPF allows modification to the hello timer interval with values between 1 and 65,535 seconds.

The default OSPF hello timer interval varies based on the OSPF network type. Changing the hello timer interval modifies the default dead interval, too. The OSPF hello timer is modified with the interface configuration submode command ip ospf hello-interval 1–65535.

53
Q

T/F: It is possible to override the default of 4xHello timer for the Dead Interval Timer value?

A

True.

The dead interval timer can be changed to a value between 1 and 65,535 seconds. The OSPF dead interval timer can be changed with the command ip ospf dead-interval 1–65535 under the interface configuration sub mode.

NOTE: Always make sure that the dead interval timer setting is greater than the hello timer setting to ensure that the dead interval timer does not reach 0 in between hello packets.

54
Q

What command will show the OSPF interval timers?

A

The timers for an OSPF interfaces are shown with the command show ip ospf interface, as demonstrated in Example 8-13. Notice the highlighted hello and dead timers.

55
Q

T/F: DR and BDR routers consume more CPU and memory than DROTHER routers.

A

True.

The DR and BDR roles for a broadcast network consume CPU and memory on the host routers in order to maintain states with all the other routers for that segment. Placing the DR and BDR roles on routers with adequate resources is recommended.

56
Q

T/F: The DR/BDR election occurs during OSPF neighborship—specifically during the last phase of 2-Way neighbor state and just before the ExStart state.

A

True.

When a router enters the 2-Way state, it has already received a hello from the neighbor. If the hello packet includes a RID other than 0.0.0.0 for the DR or BDR, the new router assumes that the current routers are the actual DR and BDR.

57
Q

Put the following OSPF adjacency states in order:

  1. ExStart
  2. Init
  3. Full
  4. Exchange Loading
  5. Down
  6. Attempt
  7. 2-Way
A

Dogs Attack Individuals To Earn Eating Lovely Food

They should be in this order:

  • Down
  • Attempt
  • Init
  • 2-Way
  • ExStart
  • Exchange Loading
  • Full

See the attached table for a description of the states.

58
Q

T/F: By default, all OSPF interfaces use a priority of 1.

A

True.

This is important during the DR and BDR election process. Any router with OSPF priority of 1 to 255 on its OSPF interface attempts to become the DR. By default, all OSPF interfaces use a priority of 1. The routers place their RID and OSPF priorities in their OSPF hellos for that segment.

59
Q

During the election process, once all the routers have agreed on the same DR, all routers for that segment become adjacent with the DR. What happens next?

A

Then the election for the BDR takes place. The election follows the same logic for the DR election, except that the DR does not add its RID to the BDR field of the hello packet.

The OSPF DR and BDR roles cannot be preempted after the DR/BDR election. Only upon the failure (or process restart of the DR or BDR) does the election start to replace the role that is missing.

60
Q

What is a command to view the role of an OSPF interface? i.e. DR, BDR, DROTHER

A

The easiest way to determine the interface role is by viewing the OSPF interface with the command show ip ospf interface brief.

Example 8-14 shows this command executed on R1 and R3 of the sample topology. Notice that R1’s Gi0/2 interface is the DR for the 10.1.1.0/24 network (as no other router is present), and R1’s Gi0/1 interface is DROTHER for the 10.123.4.0/24 segment. R3’s Gi0/1 interface is the BDR for the 10.123.4.0/24 network segment.

61
Q

T/F: Modifying a router’s RID for DR placement is a bad design strategy.

A

True.

A better technique involves modifying the interface priority to a higher value than the existing DR has.

Remember that the first factor in determining DR/BDR is the OSPF priority, and the next decision point is the higher RID.

The priority can be set manually under the interface configuration with the command ip ospf priority 0–255 for IOS nodes.

62
Q

If you want to prevent a router from participating in the DR/BDR election process, what command will allow you to do so?

A

The priority can be set manually under the interface configuration with the command ip ospf priority 0–255 for IOS nodes.

Setting an interface priority to 0 removes that interface from the DR/BDR election immediately. Raising the priority above the default value (1) makes that interface more favorable compared to interfaces with the default value.

63
Q

The default OSPF network type is set based on the media used for the connection. Cisco’s implementation of OSPF considers the various media and provides five OSPF network types. What are they?

A
  1. Broadcast
  2. Non-broadcast
  3. Point-to-point
  4. Point-to-multipoint
  5. Loopback

Different media can provide different characteristics or might limit the number of nodes allowed on a segment. Frame Relay and Ethernet are a common multi-access media, and because they support more than two nodes on a network segment, the need for a DR exists. Other network circuits, such as serial links (with HDLC or PPP encapsulation), do not require a DR, and having one would just waste router CPU cycles.

The default OSPF network type is set based on the media used for the connection and can be changed independently of the actual media type used. Cisco’s implementation of OSPF considers the various media and provides five OSPF network types, as listed in Table 8-9.

64
Q

What command overrides the automatically configured setting and statically sets an interface as an OSPF ‘broadcast network’ type?

A

The interface parameter command ip ospf network broadcast overrides the automatically configured setting and statically sets an interface as an OSPF broadcast network type.

65
Q

T/F: Point to Point links use ARP to resolve IP to MAC addresses.

A

False.

There is no need since there are only two nodes. HDLC, PPP, GRE tunnels, and Pt-Pt Frame Relay connections do not need ARP.

Similarly, there is no need for a DR/BDR on a Pt-Pt link, so none exist.

66
Q

What is the command to manually set an interface as an OSPF point-to-point network type?

A

The interface parameter command ip ospf network point-to-point sets an interface as an OSPF point-to-point network type.

67
Q

T/F: The IP address of a Loopback interface is always advertised with a /32 prefix length by OSPF, even if the IP address configured on the loopback interface does not have a /32 prefix length.

A

True.

The OSPF network type loopback is enabled by default for loopback interfaces and can be used only on loopback interfaces. The OSPF loopback network type states that the IP address is always advertised with a /32 prefix length, even if the IP address configured on the loopback interface does not have a /32 prefix length.

68
Q

Review Table 8-11 on page 192 for more commands to add to flashcards after studying them.

A
69
Q

T/F: A passive interface does not send out OSPF hellos and does not process any received OSPF packets.

A

True.

CCNP ENCOR (30 decks)

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