Smaller than a /24 for BGP?

Masataka Ohta mohta at
Mon Feb 6 14:53:12 UTC 2023

Michael Bolton via NANOG wrote:

 > We would benefit from advertising /25's but it hurt's more
 > than it helps.

That is, IPv6 really hurts.

> I'm in the alarm industry and they still haven't started adopting
> IPv6. If we allow /25 subnets, some industries will never change. In
> a sense, we have to “force” them to change.

FYI, WRT routing table bloat, IPv6 having a lot longer minimum
allocation prefix than /24 (which forbid operators cut IPv6
prefixes longer than /24), that is, a lot beyond direct SRAM
look up, and, worse, needing longer TCAM word size (64 or 128
bits?) than IPv4, is, in a not so long run, a lot lot worse
than IPv4.

						Masataka Ohta

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