BCPs are stable identifiers for Best Current Practices. A BCP may consist of a single RFC or a group of RFCs related to a specific IETF process or recommended guidelines. The collection may become empty as the BCP evolves.
RFC 6441: BCP 171: Time to Remove Filters for Previously Unallocated IPv4 /8s
Best Current Practice
- L. Vegoda
- November 2011
- IETF publication
- Operations and Management Area
Abstract
It has been common for network administrators to filter IP traffic from and BGP prefixes of unallocated IPv4 address space. Now that there are no longer any unallocated IPv4 /8s, this practise is more complicated, fragile, and expensive. Network administrators are advised to remove filters based on the registration status of the address space.
This document explains why any remaining packet and BGP prefix filters for unallocated IPv4 /8s should now be removed on border routers and documents those IPv4 unicast prefixes that should not be routed across the public Internet. This memo documents an Internet Best Current Practice.
Abstract
It has been common for network administrators to filter IP traffic from and BGP prefixes of unallocated IPv4 address space. Now that there are no longer any unallocated IPv4 /8s, this practise is more complicated, fragile, and expensive. Network administrators are advised to remove filters based on the registration status of the address space.
This document explains why any remaining packet and BGP prefix filters for unallocated IPv4 /8s should now be removed on border routers and documents those IPv4 unicast prefixes that should not be routed across the public Internet. This memo documents an Internet Best Current Practice.