BCP 171

RFC 6441

Time to Remove Filters for Previously Unallocated IPv4 /8s, November 2011

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L. Vegoda
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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.

For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.

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