nanog mailing list archives
Re: maximum ipv4 bgp prefix length of /24 ?
From: Crist Clark <cjc+nanog () pumpky net>
Date: Wed, 4 Oct 2023 22:49:09 -0700
Been resisting adding to this thread... But if the assumption is that networks will always eventually totally deaggregate to the maximum, we're screwed. Routing IPv4 /32s would be nothing. The current practice of accepting /48s could swell to about 2^(48 - 3) = 2^45 = 35184372088832. What will prevent unrestricted growth of the IPv6 table if operators push everything out to /48 "to counter hijacks" or other misguided reasons? On Wed, Oct 4, 2023 at 8:14 AM Owen DeLong via NANOG <nanog () nanog org> wrote:
If you maximally disaggregate to /24, you end up with about 12M fib entries. At /25 this doubles and you double it again for every bit you move right. At /24, we are on borrowed time without walking right. Also, the CPU in most routers won’t handle the churn of a 10M prefix RIB. OwenOn Oct 4, 2023, at 03:15, Mark Tinka <mark@tinka.africa> wrote: On 10/4/23 12:11, Musa Stephen Honlue wrote: Which one is easier, 1. Convincing the tens of thousands of network operators and equipmentvendors to modify configs and code to accept more specifics than /24, orEquipment vendors can already support 10 million entries in FIB. Theyjust ask for a little bit of cash for it.Mark.
Current thread:
- Re: maximum ipv4 bgp prefix length of /24 ?, (continued)
- Re: maximum ipv4 bgp prefix length of /24 ? Owen DeLong via NANOG (Oct 02)
- Re: maximum ipv4 bgp prefix length of /24 ? Justin Wilson (Lists) (Oct 03)
- Re: maximum ipv4 bgp prefix length of /24 ? Elmar K. Bins (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Mark Tinka (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Elmar K. Bins (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Owen DeLong via NANOG (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Elmar K. Bins (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? William Herrin (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Musa Stephen Honlue (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Mark Tinka (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Owen DeLong via NANOG (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Crist Clark (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Mark Tinka (Oct 04)
- Message not available
- Re: maximum ipv4 bgp prefix length of /24 ? Mark Tinka (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Owen DeLong via NANOG (Oct 05)
- Re: maximum ipv4 bgp prefix length of /24 ? Matthew Petach (Oct 05)
- Message not available
- Message not available
- Message not available
- Re: maximum ipv4 bgp prefix length of /24 ? Mark Tinka (Oct 04)
- Re: maximum ipv4 bgp prefix length of /24 ? Owen DeLong via NANOG (Oct 05)
- Re: maximum ipv4 bgp prefix length of /24 ? William Herrin (Oct 05)
- Re: maximum ipv4 bgp prefix length of /24 ? Delong.com via NANOG (Oct 09)
- Re: maximum ipv4 bgp prefix length of /24 ? Matthew Petach (Oct 09)