Re: maximum ipv4 bgp prefix length of /24 ?
On 10/5/23 08:24, Geoff Huston wrote:
The IPv6 FIB is under the same pressure from more specifics. Its taken 20 years to get there, but the IPv6 FIB is now looking stable at 60% opf the total FIB size [2]. For me, thats a very surprising outcome in an essentially unmanaged system.
Were you expecting it to be lower than IPv4? Mark.
Ratio of FIB to RIB is only part of the equation. IPv6 is NOT under the disaggregation pressure that IPv4 is under because there is no pressure (other than perhaps scarcity mentality from those that don’t properly understand IPv6) to dense-pack IPv6 assignments or undersize IPv6 allocations. Look at the difference in prefixes per ASN across the two tables and that tells a much grimmer story for IPv4 in terms of RIB growth vs. IPv6. Owen
On Oct 4, 2023, at 23:30, Mark Tinka <mark@tinka.africa> wrote:
On 10/5/23 08:24, Geoff Huston wrote:
The IPv6 FIB is under the same pressure from more specifics. Its taken 20 years to get there, but the IPv6 FIB is now looking stable at 60% opf the total FIB size [2]. For me, thats a very surprising outcome in an essentially unmanaged system.
Were you expecting it to be lower than IPv4?
Mark.
On Wed, Oct 4, 2023 at 11:33 PM Mark Tinka <mark@tinka.africa> wrote:
On 10/5/23 08:24, Geoff Huston wrote:
The IPv6 FIB is under the same pressure from more specifics. Its taken 20 years to get there, but the IPv6 FIB is now looking stable at 60% opf the total FIB size [2]. For me, thats a very surprising outcome in an essentially unmanaged system.
Were you expecting it to be lower than IPv4?
Mark.
I've dug through the mailman mirror on nanog.org, and there's currently no post by Geoff Huston saying that: https://community.nanog.org/search?q=geoff%20huston%20order%3Alatest But I'll play along. There's significantly less pressure to deaggregate IPv6 space right now, because we don't see many attacks on IPv6 number resources. Once we start to see v6 prefix hijackings, /48s being announced over /32 prefixes to pull traffic, then I think we'll see IPv6 deaggregation completely swamp IPv4 deaggregation. Either that, or content sites will simply turn off IPv6 AAAA records during periods of attack, and let the traffic shift back to IPv4 instead. When your IPv4 space gets hijacked, there's no fallback; you announce /24s, because that's all you *can* do. When your IPv6 space gets hijacked, there's always IPv4 as the fallback, so there's less pressure to announce /48s for all your space, just in case someone tries to hijack itl. Otherwise, we would already be seeing the IPv6 deaggregation completely overwhelming the IPv4 deaggregation. Thanks! Matt
participants (3)
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Mark Tinka -
Matthew Petach -
Owen DeLong