Deal of The Day! Hurry Up, Grab the Special Discount - Save 25% - Ends In 00:00:00 Coupon code: SAVE25
Welcome to Pass4Success

- Free Preparation Discussions
Mail Us support@pass4success.com
Location US
Mob_nav_barsMENU

Juniper JN0-351 Exam - Topic 6 Question 51 Discussion

Actual exam question for Juniper's JN0-351 exam
Question #: 51
Topic #: 6
[All JN0-351 Questions]

You are configuring an IS-IS IGP network and do not see the IS-IS adjacencies established. In this scenario, what are two reasons for this problem? (Choose two.)

Show Suggested Answer Hide Answer
Suggested Answer: A, D

Option A suggests that the MTU is not at least 1492 bytes.This is correct because IS-IS requires a minimum MTU of 1492 bytes to establish adjacencies1.If the MTU is less than this, IS-IS adjacencies will not be established1.

Option D suggests that the lo0 interface is not included as an IS-IS interface.This is also correct because the loopback interface (lo0) is typically used as the router ID in IS-IS1.If the loopback interface is not included in IS-IS, it could prevent IS-IS adjacencies from being established1.

Therefore, options A and D are correct.


by Sheridan at Jan 05, 2026, 05:16 AM

Limited Time Offer

25%

Off

Get Premium JN0-351 Questions as Interactive Web-Based Practice Test or PDF

Contribute your Thoughts:

0/2000 characters
Submit Cancel
Matthew
I think A and C are likely reasons. MTU issues can really mess things up.
upvoted 0 times
...
Stephaine
5 days ago
Totally agree with C), mismatched areas are a big deal!
upvoted 0 times
...
Yuonne
10 days ago
B) subnets being /30 isn't a requirement for IS-IS, right?
upvoted 0 times
...
Marshall
15 days ago
Wait, does the lo0 interface really need to be included?
upvoted 0 times
...
Linwood
20 days ago
I think C) is a common mistake too!
upvoted 0 times
...
Marquetta
26 days ago
A) MTU issues can definitely cause adjacency problems.
upvoted 0 times
...
Matthew
1 month ago
Ah, the good old IS-IS adjacency problems. Brings back memories of my CCIE lab days. A and C are spot on.
upvoted 0 times
...
Ressie
1 month ago
The /30 subnet thing is just silly. Who uses that for an IGP these days? A and C are the way to go.
upvoted 0 times
...
Lucina
2 months ago
Haha, I bet the person who wrote this question was an OSPF fan trying to trick us. IS-IS is way cooler than that old protocol.
upvoted 0 times
...
Marylin
2 months ago
I agree, A and C are the right choices. Mismatched areas can definitely cause issues with IS-IS adjacencies.
upvoted 0 times
...
Denise
2 months ago
The correct answers are A and C. MTU needs to be at least 1492 bytes, and the Level 2 routers must have the same area.
upvoted 0 times
...
Cheryl
2 months ago
I thought the /30 subnet was more relevant for point-to-point links, but I’m not convinced it’s a reason for adjacencies not forming.
upvoted 0 times
...
Izetta
3 months ago
I practiced a question like this, and I feel like the loopback interface not being included could also be a factor, so D might be worth considering.
upvoted 0 times
...
Carolynn
3 months ago
I’m not entirely sure, but I think mismatched areas could definitely cause issues, so maybe C is correct too.
upvoted 0 times
...
Rusty
3 months ago
I remember something about MTU settings being crucial for adjacencies, so A might be a good choice.
upvoted 0 times
...
Allene
3 months ago
Ugh, IS-IS adjacencies can be tricky. I'm going to have to really think through the key configuration requirements here. The areas and loopback interface are good places to start troubleshooting.
upvoted 0 times
...
Katie
3 months ago
I feel pretty confident about this one. The mismatched areas and missing loopback interface are the two most likely culprits here. The subnet size and MTU are good to verify, but those aren't the main problems.
upvoted 0 times
...
Pete
3 months ago
Okay, let's see. I'm pretty sure the mismatched areas would definitely cause an issue with the adjacency. And I think the loopback interface needs to be included as well. The subnet size and MTU are good things to double-check too.
upvoted 0 times
...
Gerald
4 months ago
Hmm, this one has me a bit stumped. I know the IS-IS adjacency has some specific configuration needs, but I'm not remembering all the details off the top of my head.
upvoted 0 times
...
Hubert
4 months ago
I think the key here is to focus on the IS-IS adjacency requirements. The MTU and subnet size seem like they could be factors, but I'm not totally sure.
upvoted 0 times
...

Save Cancel