300-420 Question 25
Select 2An enterprise network is being designed to support multiple address families for routing, including IPv4 unicast, IPv6 unicast, and multicast. Which considerations must be accounted for when configuring a routing protocol like BGP to support these address families?
- A
The BGP process must be enabled with specific address-family commands for each desired address family.
- B
Separate BGP Autonomous System Numbers (ASNs) must be configured for each address family.
- C
The underlying transport (TCP sessions) between BGP peers must support both IPv4 and IPv6 simultaneously for dual-stack operation.
- D
Each address family requires its own routing table, which is managed separately by the BGP router.
- E
BGP neighbors must be configured separately for each address family to establish sessions.
Show answer and explanation
Correct answers: A, D
Explanation
When designing a network to support multiple address families in BGP, it is essential to configure specific address-family commands to enable and manage each type of routing information (e.g., IPv4, IPv6, multicast). Each address family is managed independently within BGP, requiring its own routing table. However, the same ASN can be used across all address families, and a single BGP session can negotiate support for multiple address families without needing separate neighbor configurations.
- A. Correct.
Correct. BGP uses address-family configurations to enable specific address families such as IPv4, IPv6, or multicast. These configurations allow BGP to advertise and exchange routes for the corresponding address family.
- B. Incorrect.
Incorrect. A single BGP Autonomous System Number (ASN) can be used for multiple address families. Separate ASNs are not required for each address family.
- C. Incorrect.
Incorrect. While dual-stack operation may require both IPv4 and IPv6 transport, BGP sessions for IPv4 and IPv6 address families can operate independently, and this is not a strict requirement for addressing families.
- D. Correct.
Correct. Each address family in BGP is managed independently, requiring a separate routing table. This ensures proper isolation of routing information between address families.
- E. Incorrect.
Incorrect. BGP neighbors are not configured separately for each address family. Once a BGP session is established, the session can support multiple address families through negotiation and configuration.