New Year Sale 2026! 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 JN0-664 Exam - Topic 2 Question 55 Discussion

Actual exam question for Juniper's JN0-664 exam
Question #: 55
Topic #: 2
[All JN0-664 Questions]

In which two ways does OSPF prevent routing loops in multi-area networks? (Choose two.)

Show Suggested Answer Hide Answer
Suggested Answer: C, D

OSPF is an interior gateway protocol that uses link-state routing to exchange routing information among routers within a single autonomous system. OSPF prevents routing loops in multi-area networks by using two methods: area hierarchy and SPF algorithm. Area hierarchy is the concept of dividing a large OSPF network into smaller areas that are connected to a backbone area (area 0). This reduces the amount of routing information that each router has to store and process, and also limits the scope of link-state updates within each area.All areas are required to connect to area 0 either directly or through virtual links2. SPF algorithm is the method that OSPF uses to calculate the shortest path to each destination in the network based on link-state information. The SPF algorithm runs on each router and builds a shortest-path tree that represents the topology of the network from the router's perspective.The SPF algorithm prunes looped paths within an area by choosing only one best path for each destination3.


by Pok at Nov 25, 2025, 09:26 PM

Limited Time Offer

25%

Off

Get Premium JN0-664 Questions as Interactive Web-Based Practice Test or PDF

Contribute your Thoughts:

0/2000 characters
Submit Cancel
Billye
11 hours ago
Wait, are all areas really required to connect as a full mesh? That sounds off.
upvoted 0 times
...
Mabel
6 days ago
SPF algorithm is crucial for pruning loops, no doubt.
upvoted 0 times
...
Albert
11 days ago
I thought the LFA algorithm was for fast reroute, not loop prevention?
upvoted 0 times
...
Chau
16 days ago
Definitely agree, that's a key point!
upvoted 0 times
...
Arthur
21 days ago
OSPF requires all areas to connect to area 0.
upvoted 0 times
...
Ettie
26 days ago
Haha, A is a good one. A full mesh of areas, really? That would be a nightmare to configure.
upvoted 0 times
...
Alexis
1 month ago
C and D make the most sense to me. Can't have loops in OSPF!
upvoted 0 times
...
Dorian
1 month ago
I thought B was the answer. The LFA algorithm sounds like it would do the trick.
upvoted 0 times
...
Lisbeth
1 month ago
I feel like I’ve seen something about areas needing to connect in a full mesh, but that doesn’t sound right for OSPF.
upvoted 0 times
...
Felice
2 months ago
I’m a bit confused; I thought the LFA algorithm was more about fast reroute rather than loop prevention.
upvoted 0 times
...
Kandis
2 months ago
Ah, I remember learning about this in class. OSPF uses the concept of areas, and all areas have to connect to the backbone area 0 to prevent routing loops across the entire network. The SPF algorithm also helps identify and remove any looped paths within a single area. I'll go with C and D.
upvoted 0 times
...
Mireya
2 months ago
I'm pretty confident on this one. OSPF prevents loops by requiring all areas to connect to the backbone area 0, and the SPF algorithm helps identify and remove any looped paths within an area. I'll select C and D.
upvoted 0 times
...
Isaac
2 months ago
C and D are the correct answers. The OSPF area 0 requirement and the SPF algorithm are key to preventing routing loops.
upvoted 0 times
...
Kasandra
2 months ago
Hmm, this is a tricky one. I know OSPF has some mechanisms to prevent loops, but I'm not totally clear on the details. I'll have to think this through carefully and use the process of elimination to narrow down the options.
upvoted 0 times
...
Mable
2 months ago
I remember practicing a question about OSPF and the SPF algorithm, so I think that might be one of the answers for preventing loops.
upvoted 0 times
...
Emiko
3 months ago
D is definitely the way to go. The SPF algorithm is the bread and butter of OSPF loop prevention.
upvoted 0 times
...
Sherman
3 months ago
I think one way OSPF prevents loops is by requiring all areas to connect to area 0, but I'm not entirely sure about the second option.
upvoted 0 times
...
Gracia
3 months ago
Okay, I think I've got this. OSPF uses the concept of areas to prevent loops, with all areas required to connect to the backbone area 0. And the SPF algorithm helps prune any potential looped paths within an area. I'll go with C and D.
upvoted 0 times
...
Lilli
3 months ago
I'm pretty sure the answer has something to do with the OSPF area structure, but I'm not sure exactly how it prevents loops. I'll need to review the OSPF concepts again.
upvoted 0 times
...

Save Cancel