300-410 Question 130
Select 3A network engineer is configuring BGP for a dual-stack environment where both IPv4 and IPv6 address families are required. Which steps must the engineer perform to enable BGP sessions for both address families?
- A
Define separate neighbor statements for IPv4 and IPv6 under the BGP process.
- B
Activate the IPv4 and IPv6 address families using the 'address-family' command in the BGP configuration.
- C
Use the 'neighbor' command to specify the remote AS for both IPv4 and IPv6 peers.
- D
Enable IPv4 and IPv6 BGP sessions globally using the 'bgp dual-stack' command.
- E
Configure the 'network' command under each address family to advertise specific prefixes.
Show answer and explanation
Correct answers: B, C, E
Explanation
In a dual-stack BGP setup, IPv4 and IPv6 address families must be explicitly configured. The 'address-family' command activates the respective address family, while the 'neighbor' command specifies the remote autonomous system. Additionally, the 'network' command is used to advertise prefixes for each address family. Defining separate neighbor statements for IPv4 and IPv6 is not mandatory as long as the address families are activated under the respective neighbor configuration.
- A. Incorrect.
Defining separate neighbor statements for IPv4 and IPv6 is not required because a single neighbor statement can support multiple address families as long as the address families are activated.
- B. Correct.
The 'address-family' command must be used to activate BGP sessions for IPv4 and IPv6, as BGP needs explicit configuration for each address family.
- C. Correct.
The 'neighbor' command is required to specify the remote AS for both IPv4 and IPv6 peers, as this establishes the BGP session.
- D. Incorrect.
The 'bgp dual-stack' command does not exist in Cisco IOS. Instead, address families must be configured individually for dual-stack environments.
- E. Correct.
The 'network' command is necessary under each address family to advertise prefixes in BGP for both IPv4 and IPv6.