> On Apr 24, 2018, at 09:15, Pete Heist <p...@eventide.io> wrote: > > >> On Apr 24, 2018, at 7:58 AM, Jonathan Morton <chromati...@gmail.com> wrote: >> >> Turning NAT support on by default might actually be reasonable, since it >> doesn't really break anything if it's not needed - it just eats a bit of CPU >> with unnecessary conntrack lookups. > > I would be for it, if it eats say < 1% additional CPU, and preferably less. I > expect the impact to increase with packet rates. > >> For the flowmodes, basically triple-isolate's raison d'être is to be a >> reasonable default which (usually) gives most of the benefits of the "dual" >> modes, without needing to know a-priori anything about network topology. In >> the most typical application, the distinction can be seen in whether the >> qdisc is attached to an IFB or a physical interface, but in deployments that >> we'd *like* to see, the opposite cases easily occur. To do anything more >> sophisticated, we'd need to watch some traffic and guess after a while, and >> that doesn't feel right. > > Yeah, I see. The same could be done with nat. There could be an auto-detect > phase where nat lookups are performed and not to determine if it’s needed. > But if these detections didn’t work with near-perfect reliability, it would > complicate troubleshooting.
IMHO, auto-detection would at least require a dedicated keyword, like "detect-nat" that would be reported in the tc -s qdisc output for cake as long as the detection phase is active and would be replaced by the appropriate "nat" or "nonat" keyword in the tc -s qdisc output after the phase is done (there should be no ambiguity). But overall I believe that this is adding more confusion. That said I am all for making nat the default, even though it would be nice to have measurements showing its cost. > _______________________________________________ > Cake mailing list > Cake@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cake _______________________________________________ Cake mailing list Cake@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cake