CCIE Service Provider (legacy) — Question 3

A network engineer is designing the BGP architecture with a requirement of preventing the AS from becoming a Transit AS path, using the following configuration: router bgp 65000 neighbor 10.0.0.1 route-map BGP-ROUTE-POLICY in
The goal is to prevent routes learned from 10.0.0.1 from being advertised to any other eBGP peering in the AS 65000. What command should be used within the route map to achieve this goal while keeping existing route policies in place?

Answer options

• A. set community no-export additive
• B. set community no-advertise
• C. set community no-advertise additive
• D. set community no-export

Correct answer: C

Explanation

The correct answer is C, as 'set community no-advertise additive' prevents the advertisement of the routes to other eBGP peers while preserving existing route policies. Option A, 'set community no-export additive', would also prevent advertisement but does not align with the requirement. Option B, 'set community no-advertise', does not maintain existing policies, and option D, 'set community no-export', does not provide the additive functionality required to keep other policies intact.