Exam 300-410 All Questions

View all questions & answers for the 300-410 exam

Exam 300-410 topic 1 question 540 discussion

Actual exam question from Cisco's 300-410

Question #: 540
Topic #: 1

Refer to the exhibit. Router R4 is configured correctly with default OSPF values. A network engineer configured R7 for OSPF. R7 must not be elected as a DR for the segment between R4-R7. The adjacency between R4 and R7 failed to form. Which configuration resolves the issue?

Show Suggested Answer

Suggested Answer: C 🗳️

by Bombbear_W at Feb. 18, 2024, 1:50 a.m.

Comments

Submit Cancel

Chiaretta

Highly Voted 1 year, 2 months ago

Selected Answer: C

C is correct because the default value of OSPF hello and death interval are 10 and 40. ip ospf priority must be 0.

upvoted 6 times

...

packl74

Most Recent 7 months, 3 weeks ago

As you can read in the qst Router R4 is configured correctly with default OSPF values¨ the timeH default 10, the timeD default 40, and priroity 0 make de R7 ineligible for DR election. if yo choise the option D the adjacency no up becakuse no match the timer´s

upvoted 3 times

...

bk989

9 months, 3 weeks ago

Disregard my previous comment. Answer = C.

upvoted 2 times

bk989

9 months, 3 weeks ago

I misread the exhibit wrong, thought the output was for R4 in the image, when it shows R7. The only answer thst makes sense is C. A and B have wrong priorities. We don't need DR/BDR on a non-broadcast. C is only one that makes sense.

upvoted 1 times

...

bk989

10 months, 1 week ago

This was my original comment and I am updating: the only possibility is C or D as it sets ospf priority to 0. Then choose between broadcast or non-broadcast. fastethert interfaces are usually broadcast (by default) so if we do se it to non-broadcast then the other side better hopefully be non-broadcast also. And finally the timers 10 40 match for broadcast (assuming the other side is broadcast). However D would also work if the other side of the link didn't have default ospf fastethernet settings. Best answer is C. However thinking about it more, I realize OSPF adjececny to for the need for a DR/BDR must be same on both sides. R4 is point-to-point, no need DR/BDR. Both broadcast and non-broadcast have a need for DR/BDR. In choosing between C or D: both timers are wrong. D doesn't specify any neighbors, on non-broadcast networks we specify neighbors.

upvoted 1 times

bk989

10 months, 1 week ago

When I labbed this in GNS I had R1 point to point , 5 and 15 second timers and R2 broadcast default 10 40 second timers., and no adjacency. IOU1(config-if)#ip ospf dead IOU1(config-if)#ip ospf dead-interval 40 IOU1(config-if)#ip ospf hello-interval 10 IOU1(config-if)#do clear ip ospf process Reset ALL OSPF processes? [no]: yes Aug 15 02:47:05.600: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Ethernet0/1 from LOADING to FULL, Loading Done I was able to form adjacecny as long as timers were same, one side point-to-point other side broadcast.

upvoted 1 times

bk989

10 months, 1 week ago

On R1 I made non-broadcast and adjacecny goes down: IOU1(config-if)#ip ospf net non IOU1(config-if)#ip ospf net non-broadcast IOU1(config-if)#ip ospf net non-broadcast IOU1(config-if)#ip ospf net non-broadcast IOU1(config-if)# *Aug 15 02:48:29.933: OSPF-1 ADJ Et0/1: Interface going Down *Aug 15 02:48:29.933: OSPF-1 ADJ Et0/1: 2.2.2.2 address 1.1.1.2 is dead, state DOWN Then I statically configure neighbor: IOU1(config-router)#do show ip ospf neighbor IOU1(config-router)#neighbor 1.1.1.2 On R1: IOU1#show ip ospf ne IOU1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface N/A 0 ATTEMPT/DROTHER - 1.1.1.2 Ethernet0/1

upvoted 1 times

bk989

10 months, 1 week ago

On R2 IOU2#show ip ospf neighbor IOU2# The only answer that works is C. However the timers are off.

upvoted 1 times

bk989

10 months ago

The timers work if R7 is set as point to point - timers of point to point = 10 40

upvoted 1 times

...

[Removed]

10 months, 4 weeks ago

Selected Answer: C

C is corerct

upvoted 2 times

...

TonyTe0

1 year ago

Answer: C "R7 must !! not !! be elected as a DR" -> A neighbor with priority 0 is considered ineligible for DR election. The default values are 10 seconds for the hello time, and 40 seconds for the dead time. The usual rule of thumb with OSPF is to keep the dead time value four times the hello interval. However, this is not a strict rule.

upvoted 2 times

...

Broekie

1 year ago

Selected Answer: C

"R7 must !! not !! be elected as a DR" A neighbor with priority 0 is considered ineligible for DR election. So i agree with bk989 comment.

upvoted 2 times

...

a9b616e

1 year ago

B makes more sense as a result

upvoted 1 times

...

a9b616e

1 year ago

An OSPF priority of 0 keeps a router from being DR/BDR. Default priority is 1 and priority value of 255 makes. everything else about C is correct save for the priority value

upvoted 1 times

...

Bombbear_W

1 year, 4 months ago

What are the answers? The images are corrupted!!!

upvoted 1 times

bk989

1 year, 3 months ago

the only possibility is C or D as it sets ospf priority to 0. Then choose between broadcast or non-broadcast. fastethert interfaces are usually broadcast (by default) so if we do se it to non-broadcast then the other side better hopefully be non-broadcast also. And finally the timers 10 40 match for broadcast (assuming the other side is broadcast). However D would also work if the other side of the link didn't have default ospf fastethernet settings. Best answer is C.

upvoted 1 times

...