300-440 Question 86
Select 3You are configuring a router with BGP to support both IPv4 and IPv6 address families. Which of the following configurations are required to enable BGP for both address families?
- A
Use the 'address-family ipv4' and 'address-family ipv6' commands under the BGP configuration mode.
- B
Enable 'neighbor activate' within each address-family configuration mode.
- C
Configure 'dual-stack' under the BGP process to enable both IPv4 and IPv6.
- D
Assign IPv4 and IPv6 addresses to the router's interfaces used for BGP peering.
- E
Specify the 'af-ipv4-ipv6' command in global configuration to enable both address families.
Show answer and explanation
Correct answers: A, B, D
Explanation
To enable BGP for both IPv4 and IPv6, you need to define the respective address families using the 'address-family ipv4' and 'address-family ipv6' commands. Additionally, you must activate the neighbor relationships within each address-family configuration mode using the 'neighbor activate' command. Finally, the router must have IPv4 and IPv6 addresses assigned to the interfaces used for peering to establish BGP sessions. Options 3 and 5 are invalid because they refer to non-existent commands.
- A. Correct.
Correct: The 'address-family ipv4' and 'address-family ipv6' commands are required to define BGP support for each respective address family.
- B. Correct.
Correct: The 'neighbor activate' command is used within the address-family configuration mode to enable BGP peering for that specific address family.
- C. Incorrect.
Incorrect: There is no 'dual-stack' configuration command in BGP; IPv4 and IPv6 are managed separately using address-family configurations.
- D. Correct.
Correct: BGP requires that the router's interfaces used for peering have valid IPv4 and IPv6 addresses assigned.
- E. Incorrect.
Incorrect: The 'af-ipv4-ipv6' is not a valid Cisco IOS command for enabling BGP address families.