On Tuesday 19 June 2001 05:01, Andi Kleen wrote: > > How does equal cost multipath in linux work? Does it round robin each > > packet as they come in? > > No, it round robins routes. A route is a (SRCIP, DSTIP, TOS) tripple > [simplified]. I understand that it keep switching between "equivalant" routes. But does it decide each packet on its own merits, or does a tcp session keep following the same route? IOW, a packet hits the routing code; two routes match. Does the fact that this packet is part an established TCP session have any sway over which route gets picked? > There are other ways in Linux to do per packet round-robin though; but it > is not recommended because it reorders packets badly and kills performance > for most network protocols. I know about packet reordering. That's one of the reason why I want sessions to be "sticky". > > Do routing daemons on linux install multiple default routes? Can they? > > Multiple default routes are a different thing; it does active failover > unlike standard multipath routes (the later keep that job currently for the > routing daemon) Do you mean that ECMP treats default routes differently? And what qualifies as "active failover"? Does it stop trying to use a default route if the neighbor is unreachable? And how does it determine reachability? > Latest zebra seems to support multipath routes e.g. with > OSPF and there is also a patchkit for gated. Where would I find this patchkit for gated? Thanks for your help, Mordy -- Mordy Ovits Network Engineer Bloomberg L.P. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
