A network engineer is troubleshooting an IS-IS flooding loop. The engineer suspects that a router is reflooding an LSP back to the router it received it from. Which mechanism is primarily responsible for preventing this?

The use of a mesh group on the interface.

The router checks its LSP database and does not reflood an LSP to the neighbor from which it was originally received.

The remaining lifetime field in the LSP header.

The sequence number in the LSP header.

Which statement correctly describes the basic mechanism of LSP flooding in IS-IS?

LSPs are sent to all neighbors except the one from which the LSP was received.

LSPs are sent only to Level 2 routers to reduce overhead.

LSPs are sent only to the designated router, which then redistributes them to all other routers.

LSPs are sent only to neighbors that have requested the LSP via a CSNP.

When an IS-IS router receives an LSP from a neighbor, what is the first step it performs before deciding whether to reflood it?

It runs the SPF algorithm to see if the LSP changes the shortest path tree.

It sends a PSNP to acknowledge receipt of the LSP.

It immediately forwards the LSP to all other neighbors to minimize delay.

It checks the LSP against its link-state database to determine if it is new or newer than the stored copy.

In IS-IS, what is the primary purpose of flooding Link State PDUs (LSPs)?

To assign IP addresses to interfaces

To establish adjacencies with neighboring routers

To distribute link-state information so all routers build a consistent topology database

To authenticate routing updates between peers

Juniper NetworksCertified Professional, Service Provider Routing and Switching (JNCIP-SP)

Domain 2Objective 3

LSP Flooding JN0-664 Practice Questions (Page 3)

Part of the IS-IS domain, which makes up ~18% of our current practice bank. Juniper Networks does not publish an official question count, but from its 90-minute exam (~35–60 total, ~6–11 in this domain), expect 1–1 from this objective — we provide 22 practice questions to prepare you well beyond it. (estimate)

22questions here

5free pages

6concepts

Questions 11–15

11application · medium
A network engineer is troubleshooting an IS-IS flooding loop. The engineer suspects that a router is reflooding an LSP back to the router it received it from. Which mechanism is primarily responsible for preventing this?
Select an answer first
12foundation · easy
Which statement correctly describes the basic mechanism of LSP flooding in IS-IS?
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13foundation · easy
In a dense IS-IS topology with many parallel links between routers, which technique reduces the number of LSP copies flooded on a set of links?
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14foundation · easy
When an IS-IS router receives an LSP from a neighbor, what is the first step it performs before deciding whether to reflood it?
Select an answer first
15foundation · easy
In IS-IS, what is the primary purpose of flooding Link State PDUs (LSPs)?
Select an answer first

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