From: Nikolay Aleksandrov <niko...@cumulusnetworks.com> Date: Tue, 14 Mar 2017 17:58:46 +0200
> On 14/03/17 17:55, Stephen Hemminger wrote: >> On Tue, 14 Mar 2017 17:36:15 +0200 >> Nikolay Aleksandrov <niko...@cumulusnetworks.com> wrote: >> >>> This patch adds support for ECMP hash policy choice via a new sysctl >>> called fib_multipath_hash_policy and also adds support for L4 hashes. >>> The current values for fib_multipath_hash_policy are: >>> 0 - layer 3 (default) >>> 1 - layer 4 >>> If there's an skb hash already set and it matches the chosen policy then it >>> will be used instead of being calculated (currently only for L4). >>> In L3 mode we always calculate the hash due to the ICMP error special >>> case, the flow dissector's field consistentification should handle the >>> address order thus we can remove the address reversals. >>> >>> Signed-off-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com> >> >> It is good to see ECMP come back from the grave. >> Linux used to support it long ago but was abandoned after it was unstable >> and removed from iproute2 in 2012. >> >> The old API was through route attributes which makes more sense than >> doing it with sysctl. It makes more sense to use netlink instead. >> Therefore please go back and do something like the old API rather than doing >> it through >> sysctl. >> > > That's what my initial version did, but this was discussed during NetConf in > Seville > and it was decided that it's best to make a global sysctl, thus the change. Correct, we discussed this, and we all agreed to only have a sysctl for now.
