nanog mailing list archives

Re: ECN

From: Toke Høiland-Jørgensen via NANOG <nanog () nanog org>
Date: Wed, 13 Nov 2019 17:50:28 +0100



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

Current thread:

Re: ECN, (continued)
- - - Re: ECN Lukas Tribus (Nov 13)
    - Re: ECN Saku Ytti (Nov 14)
    - Re: ECN Tore Anderson (Nov 13)
    - Re: ECN Warren Kumari (Nov 13)
    - TCP and anycast (was Re: ECN) Anoop Ghanwani (Nov 13)
    - Re: TCP and anycast (was Re: ECN) Bill Woodcock (Nov 14)
    - Re: TCP and anycast (was Re: ECN) William Herrin (Nov 14)
    - Re: TCP and anycast (was Re: ECN) Randy Bush (Nov 14)
    - Re: TCP and anycast (was Re: ECN) Christopher Morrow (Nov 14)
    - Re: TCP and anycast (was Re: ECN) Randy Bush (Nov 14)
    - Message not available
    - Re: ECN Toke Høiland-Jørgensen via NANOG (Nov 13)
    - Re: ECN Matt Corallo (Nov 13)
    - Re: ECN Anoop Ghanwani (Nov 13)
    - Re: ECN Owen DeLong (Nov 13)
    - Re: ECN Toke Høiland-Jørgensen via NANOG (Nov 14)
    - Re: ECN Jon Lewis (Nov 13)