300-440 Question 89
Select 3A network engineer is configuring BGP on a router to support both IPv4 and IPv6 address families. Which configuration step is required to enable BGP to advertise and process both IPv4 and IPv6 routes?
- A
Activate the IPv4 unicast address family under the BGP configuration.
- B
Activate the IPv6 unicast address family under the BGP configuration.
- C
Enable dual-stack routing on the router using the 'ip dual-stack enable' command.
- D
Configure the router ID for the BGP instance.
- E
Ensure that neighbor relationships are defined for both IPv4 and IPv6 address families.
Show answer and explanation
Correct answers: A, B, E
Explanation
To enable BGP to advertise and process both IPv4 and IPv6 routes, the respective address families (IPv4 unicast and IPv6 unicast) must be activated under the BGP configuration. Additionally, neighbor relationships must be specified for each address family explicitly. Configuring the router ID is important for the overall BGP process but not directly tied to enabling address families. The idea of a 'dual-stack enable' command is incorrect as BGP relies on explicit address family and neighbor configurations.
- A. Correct.
Correct: Activating the IPv4 unicast address family is required to allow BGP to process and advertise IPv4 routes.
- B. Correct.
Correct: Activating the IPv6 unicast address family is required to allow BGP to process and advertise IPv6 routes.
- C. Incorrect.
Incorrect: Dual-stack routing does not require a specific command like 'ip dual-stack enable'. IPv4 and IPv6 can operate simultaneously without this command.
- D. Incorrect.
Incorrect: While configuring the router ID is important for BGP functionality, it is not specifically required to enable both IPv4 and IPv6 address families.
- E. Correct.
Correct: Neighbor relationships must be defined for each address family (IPv4 and IPv6) separately in BGP configuration to ensure proper operation.