H12-891_V1-0 practice question 7 of 35

The following description of the attributes of BGP is correct?( Single choice questions).

Answer options

A: The AS deficit of the adjacent AS is ranked at the far right of the list of AS_Path in the BGP route entry.

B: When the Correct answer

C: BGP Speaker publishes a route learned from an EBGP peer to an IBGP peer, it does not change the next hop attribute of that routing information.

D: Local_Pref is valid only between EBGP peers and is not advertised to third-party AS.

E: A route can have only one community attribute value.

Correct Answer:

B. When the

Explanation

According to the BGP specification (RFC 4271), when a BGP speaker receives a route from an External BGP (EBGP) peer, it advertises this route to its Internal BGP (IBGP) peers without changing the NEXTHOP attribute. The next hop remains the IP address of the external peer. This behavior necessitates that all IBGP routers have a route to the next hop, often achieved via an IGP or by using the next-hop-self command on the advertising router.

Why Incorrect

A. The AS number of the advertising EBGP peer is prepended to the ASPath, making it the first (leftmost) entry in the list, not the last.
C. LocalPref is a well-known discretionary attribute exchanged only between IBGP peers within the same AS to influence the outbound path; it is not sent to EBGP peers.
D. A route can be associated with multiple community attribute values simultaneously to apply various routing policies.

References

1. Huawei HedEx Documentation, NE40E V800R012C10 Configuration Guide - BGP, "BGP Attributes" section, "NextHop" subsection. It states that when advertising routes learned from EBGP peers to IBGP peers, the next hop is not changed by default.

2. RFC 4271, A Border Gateway Protocol 4 (BGP-4), Section 5.1.3, "NEXTHOP". The document specifies that when a BGP speaker sends a route to an internal peer, it MUST NOT modify the NEXTHOP attribute.

3. Huawei HedEx Documentation, NE40E V800R012C10 Configuration Guide - BGP, "BGP Attributes" section, "ASPath" and "LocalPref" subsections.

Keep practicing

Take the free H12-891_V1-0 practice test

Ten exam-style questions with answers and explanations, plus the exam facts and study guides.

Start the free practice test