On Wed, 13 Nov 2019 at 22:57, Lukas Tribus <lists@ltri.eu> wrote:
In fact I believe everything beyond the 5-tuple is just a bad idea to base your hash on. Here are some examples (not quite as straight forward than the TOS/ECN case here):
ACK.
TTL: https://mailman.nanog.org/pipermail/nanog/2018-September/096871.html
IPv6 flow label: https://blog.apnic.net/2018/01/11/ipv6-flow-label-misuse-hashing/ https://pc.nanog.org/static/published/meetings/NANOG71/1531/20171003_Jaeggli... https://www.youtube.com/watch?v=b0CRjOpnT7w
It is unfortunate IPv6 flow label is so poorly specified, had it been specified clearly it could have been very very good for the Internet. Crucially sender should be able to instruct transit HOW to hash, there should be flags in flow label used by sender to indicate that flow label must be used for hash exclusively, not at all, inclusively with what ever host otherwise uses. This would give sender control over what is discreet flow. Something like this https://ytti.github.io/flow-label/draft-ytti-v6ops-flow-label.html would have been nice, but unclear if it would be possible to deliver post-fact -- ++ytti