H12-821_V1-0 practice question 22 of 30

According to BGP route selection rules, the route with the higher Local_Pref is preferred.

Full set: 219 questions

Domain BGP Principles and Configuration

Answer options
A: TRUE
B: FALSE
Correct Answer:
TRUE
Explanation

The statement is correct. The Local Preference (LocalPref) is a well-known, discretionary BGP path attribute used within a single Autonomous System (AS) to influence the selection of an outbound path for traffic. During the BGP best-path selection process, after a router has evaluated any vendor-specific attributes like Weight, it compares the LocalPref values of all available paths to a specific destination. The path with the numerically highest LocalPref value is considered more preferable and will be selected. The default LocalPref value is 100. This mechanism allows network administrators to enforce a consistent routing policy across an entire AS, directing traffic through a preferred exit point.

Why Incorrect

This is a "TRUE OR FALSE" question. The statement is factually correct according to the BGP specification and its implementation in Huawei's VRP (Versatile Routing Platform). Therefore, the "False" option is incorrect.

References

1. Huawei Official Vendor Documentation: In the Huawei NetEngine Router Product Documentation for VRP

the BGP route selection rules are explicitly listed. The documentation consistently places Local Preference as a high-priority criterion. For example

in the BGP Configuration Guide

under the section "BGP Route Selection

" the second step of the process is: "Prefers the route with the highest LocalPref."

Source: Huawei NetEngine 8000 Product Documentation

IP Routing: BGP Configuration Guide

Chapter: "BGP Features"

Section: "BGP Route Selection".

2. Peer-reviewed Academic Publications (IETF RFC): The Internet Engineering Task Force (IETF) Request for Comments (RFC) 4271 is the standard that defines BGP-4. This document is the authoritative source for the protocol's operation.

Source: IETF RFC 4271

"A Border Gateway Protocol 4 (BGP-4)"

Section 9.1.2.2

"Decision Process". Step (c) of the process states: "If the LOCALPREF attribute is present in one or more of the routes

the Decision Process selects the route with the highest LOCALPREF."

DOI Link: https://doi.org/10.17487/RFC4271

3. University Courseware: Reputable computer science and networking courses cover BGP route selection in detail

confirming this rule.

Source: Stanford University

CS 144: Introduction to Computer Networking

Lecture Slides on "Interdomain Routing (BGP)". The slides detailing the "BGP Route Selection" algorithm list "Highest Local Preference" as the first standard attribute (after the non-standard Weight) used to decide the best path.

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