300-410 Question 54
Single answerA network engineer is configuring MP-BGP to support both IPv4 and IPv6 address families on a router. After enabling BGP and activating the neighbors under the global BGP process, which additional configuration step is required to enable the router to advertise IPv6 prefixes?
- A
Enable the 'ipv6 unicast-routing' command in global configuration mode.
- B
Configure the 'address-family ipv6' stanza under the BGP process and activate the neighbors.
- C
Enable the 'neighbor advertisement ipv6' command under the BGP neighbor configuration.
- D
Add IPv6 addresses to the interfaces involved in the BGP session.
Show answer and explanation
Correct answer: B
Explanation
To enable BGP to advertise IPv6 prefixes, the network engineer must configure the 'address-family ipv6' stanza under the BGP process and activate the neighbors for that address family. MP-BGP requires address families to be explicitly defined and activated to handle IPv4, IPv6, or other address families.
- A. Incorrect.
This command enables IPv6 routing on the router but does not specifically configure BGP to advertise IPv6 address families. It is not the required step for MP-BGP address family configuration.
- B. Correct.
This is the correct step. In a Multiprotocol BGP (MP-BGP) configuration, each address family (e.g., IPv6) must be activated under the BGP process. You also need to activate neighbors under the specific address family to allow the advertisement of IPv6 prefixes.
- C. Incorrect.
This command is not a valid BGP configuration command and does not exist in the BGP syntax.
- D. Incorrect.
While IPv6 addresses must be configured on interfaces to establish BGP IPv6 peering, this step alone does not enable the advertisement of IPv6 prefixes in MP-BGP.