Huawei Certified Network Professional – Routing and Switching (HCNP-RS, legacy) — Question 19

What is the function of well-known community attribute NO_EXPORT_SUBCONFED in BGP?

Answer options

• A. Routes received carrying this value cannot be advertised outside of the confederation.
• B. Routes received carrying this value cannot be advertised to any BGP peers.
• C. Routes received carrying this value cannot be advertised to any EBGP peers.
• D. All above statements are wrong

Correct answer: C

Explanation

The correct answer is C because the NO_EXPORT_SUBCONFED community specifically prevents routes from being advertised to any EBGP peers, thus limiting their visibility outside the subconfederation. Option A is incorrect as it implies a broader restriction than intended, while option B incorrectly states that routes cannot be shared with any BGP peers, which is not accurate. Option D is also wrong since option C is indeed a valid statement.