Huawei H12-831_V1.0 Exam - Topic 4 Question 69 Discussion

Actual exam question for Huawei's H12-831_V1.0 exam

Question #: 69
Topic #: 4

[All H12-831_V1.0 Questions]

The figure shows information about an LSP (Link-State PDU) generated by an IS-IS router.

From the LSP, you can infer that the router is not the DIS (Designated Intermediate System) of the local link.

Options:

ATRUE

BFALSE

Show Suggested Answer

Suggested Answer: A

Comprehensive and Detailed In-Depth

1. Understanding the DIS (Designated Intermediate System) in IS-IS

In IS-IS, the DIS (Designated Intermediate System) is similar to the DR (Designated Router) in OSPF.

Unlike OSPF, IS-IS does not use an election based on priority; instead, the router with the highest priority becomes the DIS.

If there is a tie in priority, the router with the highest MAC address on the interface becomes the DIS.

The DIS is responsible for generating additional LSPs (pseudonode LSPs) for the link and synchronizing the database between routers.

2. How to Identify If the Router Is the DIS from the LSP

In the given LSP output, there are NO pseudonode LSPs (LSPs ending with .01).

The DIS is responsible for creating pseudonode LSPs, which represent a multi-access network in the IS-IS topology.

If the router were the DIS, it would generate both its own LSP (ending in .00) and a pseudonode LSP (ending in .01).

Since we only see an LSP ending in .00, this confirms that the router is NOT the DIS.

3. Evaluating the Answer Choices

Option A (TRUE) -- Correct:

Since no pseudonode LSP is present, the router is not the DIS.

This confirms that the statement is TRUE.

Option B (FALSE) -- Incorrect:

If the router were the DIS, it would generate pseudonode LSPs, but they are missing from the output.

Therefore, the statement is NOT false.

Final Answer:

Answe r: A (TRUE)

HCIP-Datacom-Advanced Routing & Switching Technology Reference:

IS-IS Designated Intermediate System (DIS) Selection Process

Pseudonode LSP Generation in Multi-Access Networks

IS-IS LSP Structure and Identification of DIS

by Alberto at May 02, 2025, 07:58 AM

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Cary

2 months ago

Agreed, it's clearly not the DIS based on the LSP info.

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Viki

2 months ago

Surprised to see this, I thought all routers could be DIS.

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Lashawn

2 months ago

I think it's FALSE, the router could still be the DIS.

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Phillip

3 months ago

Wait, are we sure about that? Seems a bit off to me.

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Margo

3 months ago

Definitely TRUE, the LSP indicates it's not the DIS.

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Glory

3 months ago

I feel like I might be mixing up the terms here. I thought any router could generate an LSP, but maybe only the DIS does it for the local link?

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Matthew

3 months ago

I practiced a similar question where the DIS was mentioned, and I think it was about the router's role in the network. This could be true based on that.

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Odette

4 months ago

I'm not entirely sure, but I think if the router isn't the DIS, it wouldn't generate the LSP. I need to double-check that.

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Pok

4 months ago

I remember studying the roles of routers in IS-IS, and I think the DIS is the one that generates the LSPs for the link. So, this statement might be true.

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Quentin

4 months ago

This is a good test of understanding IS-IS network concepts. I'll review the LSP details and think through the DIS role to determine the correct answer.

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Maile

4 months ago

Okay, I think I've got this. The LSP shows the router's own information, not the DIS's. So the fact that this router's LSP is being displayed means it's not the DIS. The answer must be TRUE.

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Claudio

4 months ago

I'm a bit confused by this question. The LSP data doesn't seem to directly state whether the router is the DIS or not. I'll need to think through the implications more carefully.

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Lauran

5 months ago

The question is pretty straightforward. The information provided in the LSP clearly indicates that the router is not the DIS, so the answer must be TRUE.

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