What is one reason to use the ip OSPF priority command when the OSPF routing protocol is in?

Sets the priority of a router to determine the designated OSPF router for a network.

Syntax: ip ospf priority number

no ip ospf priority

number

A number between 0 and 255 that specifies the priority of this interface.

Each broadcast and Non-Broadcast Multi-Access (NBMA) network has a designated router. If the network is a transit network, the designated router generates a link state advertisement (LSA) for the network and has other responsibilities required for the running of the protocol. The designated router is elected by the Hello Protocol.

The designated router concept reduces the amount of routing protocol traffic and reduces the size of the link-state database by enabling a reduction in the number of adjacencies required on a broadcast or non-broadcast multi-access network.

When two routers attached to a network both attempt to become the designated router, the router with the highest priority becomes the designated router. A router whose priority is set to 0 is ineligible to become designated router or backup designated router.

Use the ip ospf priority [1 - 255] command to set the priority to a value between 1 and 255.

Use the ip ospf priority 0 command to configure the router to never function as the designated router or backup designated router.

Use the no ip ospf priority command to set the priority at the default value of 1.

Factory Default: 1.

Command Mode: Interface configuration.

Example 1: In the following example, the ip ospf priority number command configures the router with a priority of 3, and the show ip ospf interface pos command displays the setting:

router(config-router)#interface pos 1/1/1
router(config-if)#ip ospf priority 3
router(config-if)#end
router#show ip ospf int pos 1/1/1

Name: POS 1/1/1
Address: 201.1.1.10
Net type:             Broadcast
State:
Area: 0.0.0.0
DR: 0.0.0.0
BDR: 0.0.0.0
Priority:             3
Cost: 10
Hello int: 10
Dead int: 40

Retrans int: 5
Transmit delay: 1

Example 2: In the following example, the ip ospf priority 0 command ensures that the router will never become the designated OSPF router for this network:

router(config)#router ospf 1
router(config-router)#network 10.1.1.0 0.0.0.255 area 0
router(config-router)#interface pos 1/1/1
router(config-if)#ip ospf priority 0

Related Commands: network area
router ospfinterface
show ip ospf interface

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Last Updated: 05/10/04 at 16:34:58

93.What is one reason to use the ip ospf priority command when the OSPFrouting protocol is in use?to influence the DR/BDR election process*to streamline and speed up the convergence processto provide a backdoor for connectivity during the convergence processto activate the OSPF neighboring process

Question 1
What is one reason to use the ip ospf priority command when the OSPF routing protocol is in use?

to activate the OSPF neighboring process
to influence the DR/BDR election process***
to provide a backdoor for connectivity during the convergence process
to streamline and speed up the convergence process

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.1.2

Question 1
What is one reason to use the ip ospf priority command when the OSPF routing protocol is in use?

to activate the OSPF neighboring process
to influence the DR/BDR election process***
to provide a backdoor for connectivity during the convergence process
to streamline and speed up the convergence process

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.1.2

Question 2
Refer to the exhibit. Fill in the blank. Use a number. The process ID that is used for OSPFv3 on the router R1 is _____.

Missed this question? See below for some assistance!

The image above shows that "IPv6 Routering Protocol is OSPF 10"; note that in OSPF for IPv6, the router ID is not the process ID, but rather it is the display as shown above.

Question 3
Match the OSPF adjacency function with the correct state. (Not all options are used.)

A. Routers receive hello packets that contain the router ID of the neighboring device.

B. On Ethernet links, a designated router (DR) and a backup designated router (BDR) is elected.

C. Routers exchange DBD packets.

A: Init State***
B: Two-Way State***
C: Exchange State***

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.2.1
The Full state indicates that the routers in the domain have converged.

Question 4
Consider the R1(config-if)# ip ospf message-digest-key 1 md5 CISCO-123 command. What is the function of the CISCO-123 portion of the command?

It is used as a password.***
It is used as the key index.
It is used to choose the type of authentication.
It is used to name the OSPFv2 process.

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.1.4 The R1(config-if)# ip ospf message-digest-key 1 md5 CISCO-123 command enables MD5 authentication for a given interface on a router that is running OSPFv2. The CISCO-123 portion is the password.

Question 5
Which command will verify that a router running OSPFv3 has received a redistributed default static route from another OSPFv3 router?

default-information originate
redistribute static
show ipv6 route***
show ip route

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.1.2
OSPFv3 is used for IPv6 routing. When the default route is redistributed, neighboring routers will display the route source as OE2 in their IPv6 routing tables. The show ip route command is used to display the IPv4 routing table. The default-information originate command is used in the source OSPFv3 router to initiate the static route redistribution. EIGRP uses the redistribute static command.

Question 6
Which three parameters should match in order for a pair of routers to form an adjacency when running OSPFv2? (Choose three.)

router ID
OSPFv2 process number
OSPFv2 type of network***
hello timer***
interface priority
subnet mask***

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.2.1
For a couple of routers that are running OSPFv2 to form an adjacency, the following parameters must match: subnet mask, network type, hello and dead timers, a corresponding network command, and the authentication information.

Question 7
Refer to the exhibit. These four routers are connected together on the same LAN segment. Based on the output shown, which of these routers will be elected to be the DR for the segment?

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.1.1
The router with the highest priority is elected as the designated router (DR). Because both R1 and R2 have the same priority (20), the router ID must be used as the tie-breaker. R2 has the higher router ID (2.2.2.2), so it is elected as the DR.

Question 8
Refer to the exhibit. Fill in the blank. Do not use abbreviations.
The command _____________ is used to display only OSPFv3 learned routes.

Missed this question? See below for some assistance!
Intuition is the only way to learn. Know the commands.

Question 9
Refer to the exhibit. Which command did an administrator issue to produce this output?

R1# show ip ospf
R1# show ip ospf neighbor
R1# show ip ospf interface serial0/0/1***
R1# show ip route ospf

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.2.2

Question 10
Refer to the exhibit. R1 and R3 are connected to each other via the local serial 0/0/0 interface. Why are they not forming an adjacency?

They are in different subnets.***
They have different routing processes.
They have different router IDs.
The connecting interfaces are configured as passive.

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.2.2
The routers need to be in the same subnet in order to form an adjacency. The routing processes can be different on each router. The router IDs must be different for routers that participate in the same routing domain. The interfaces are not passive.

Question 11

Here is a link to the PT Activity (no link)

Open the PT Activity.
Perform the tasks in the activity instructions and then answer the question. Which routers are the DR and BDR in this topology?

DR:R1 BDR:R2
DR:R6 BDR:R5
DR:R5 BDR:R3
DR:R3 BDR:R6
DR:R4 BDR:R1
DR:R3 BDR:R5***

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.1.1
Once OSPF neighbor adjacencies have formed, use the show ip ospf neighbors command to determine which router was elected the DR and which router was elected the BDR. In this scenario, R3 was elected the DR because it had the highest priority (10). R5 was elected the BDR because it had the highest router ID among eligible routers (5.5.5.5). R6 was not eligible to become the BDR because its priority was set to 0.

Question 12
What statement describes the reference bandwidth in OSPFv3?

It prevents the router from automatically adjusting the bandwidth.
It increases the speed of the link to accommodate increasing demands for bandwidth.
It should be changed if links faster than 100 Mb/s exist in the OSPF network.***
It is set to 1 Gb/s by default.

Missed this question? See below for some assistance!
Refer to curriculum topic: 5.3.1
The default reference-bandwidth for OSPF is 100 Mb/s (Fast Ethernet speed). However, most modern infrastructure devices have links that are faster than 100 Mb/s. With the default setting, all links with transmission speeds of 100 Mb/s or higher have a cost of 1. This results in Fast Ethernet, Gigabit Ethernet, and 10G Ethernet interfaces all having the same cost. Therefore, the reference-bandwidth must be changed to a higher value to accommodate networks with links faster that 100 Mb/s.

Question 13
Fill in the blank. Do not use abbreviations. The ______________ command is used when configuring an OSPFv2 router to redistribute only a static default route.

default-information originate***

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A command that you should know already.

END OF QUIZ! Answers should be correct (or at least a 90%). Make sure to comment specifically what is incorrect or what you may have missed if you did not score correctly.