Time to Remove Filters for Previously Unallocated IPv4 /8s
RFC 6441, “Time to Remove Filters for Previously Unallocated IPv4 /8s”, is a Best Current Practice document published in November 2011 by L. Vegoda. The canonical text is published by the RFC Editor.
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.
What “Best Current Practice” means
Documents the IETF community's recommended operational or procedural practice rather than a protocol specification.
The canonical text of RFC 6441 is hosted at rfc-editor.org. Available in TXT,HTML.
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