Which of the following is considered a best practice for BGP address planning?

Best Practices for BGP Address Planning:

Proper address planning ensures efficient and reliable BGP operations.

It involves using specific addresses for BGP sessions and advertising appropriate routes.

Analyzing the Options:

A. Advertising external networks into IGP: Not recommended as it can lead to IGP table bloating and instability.

B. Using system addresses for setting up iBGP sessions: This is considered a best practice. System addresses (loopback addresses) are stable and do not change even if the physical interface goes down, ensuring session stability.

C. Exporting the networks associated with the external links of eBGP peers into BGP: This is normal practice but not directly related to address planning best practices.

D. Optimizing BGP route table by exporting IGP routes into BGP: Typically, you would do the opposite (importing BGP routes into IGP selectively).

Conclusion:

Using system addresses (loopback addresses) for setting up iBGP sessions is a widely accepted best practice. It enhances the reliability and stability of the BGP sessions.

References

Nokia Border Gateway Protocol (BGP) Fundamentals documentation

Best practices in BGP design and implementation

Network stability and reliability considerations in BGP configurations