13 Nov
2019
13 Nov
'19
noon
Not ideal, sure, but if it’s only for the SYN (as you seem to indicate), splitting the flow shouldn’t have material performance degradation?
On Nov 13, 2019, at 11:51, Toke Høiland-Jørgensen <toke@toke.dk> wrote:
On 13 November 2019 17:20:18 CET, Matt Corallo <netadmin@as397444.net> wrote: This sounds like a bug on Cloudflare’s end (cause trying to do anycast TCP is... out of spec to say the least), not a bug in ECN/ECMP.
Even without anycast, an ECMP shouldn't hash on the ECN bits. Doing so will split the flow over multiple paths; avoiding that is the whole point of doing the flow-based hashing in the first place.
Anycast "only" turns a potential degradation of TCP performance into a hard failure... :)
-Toke