Huawei Certified ICT Expert – Routing and Switching (HCIE-RS) — Question 25

Which of the following causes may result in an IS-IS neighbor relationship fault? (Choose all that apply.)

Answer options

• A. The devices on two ends of a link have the same system ID.
• B. The devices on two ends of a link have inconsistent IS-IS levels.
• C. When an IS-IS Level-1 neighbor relationship is established, the devices on two ends of a link have inconsistent area addresses.
• D. The IP addresses of interfaces on two ends of a link are on different network segments.

Correct answer: C

Explanation

Option C is correct because an inconsistency in area addresses can prevent the establishment of a proper IS-IS Level-1 neighbor relationship. Options A and B are not primarily issues with neighbor relationships, as the same system ID or inconsistent IS-IS levels can sometimes still allow for a relationship to be formed. Option D is unrelated to IS-IS operation, as it pertains to IP addressing rather than IS-IS protocol specifics.