Why is it beneficial to tie bogon prefix filtering with RPKI validation?

• A. It makes filtering slower with no benefit.
• B. It reduces network performance by 50%.
• C. It provides layered defense by preventing invalid and non-authorized prefixes from being accepted.
• D. It only affects IPv6.

Answer: (C)

Combining bogon filtering with RPKI validation creates layered defense by preventing routes that shouldn’t exist and routes that aren’t properly authorized from being accepted. Bogon filtering blocks prefixes that are unallocated or reserved, so traffic from those spaces never enters the router’s forwarding decisions. RPKI validation checks that a route’s origin is authorized to announce the prefix, using cryptographic ROAs and certificate data to reject misconfigurations or hijacks.

Used together, they cover more risk: bogons guard against non-existent or mishandled address space, while RPKI guards against prefixes announced by the wrong or unauthorized origin. This reduces the chance that a bad route will be accepted, improving overall routing security. It applies to both IPv4 and IPv6, and it won’t slow networks to an unreasonable degree when implemented with sensible policies.

The other options don’t fit because they either claim no benefit or misstate scope (only IPv6) or impact on performance, which isn’t accurate.