Russ, What would be the semantics of such NH? Don't use for forwarding at all? Don't use for forwarding within ECMP bunde? Don't use in ECMP but use otherwise?
Regards, Jeff > On Oct 1, 2016, at 7:59 PM, Russ White <[email protected]> wrote: > > Y'all -- > > I would like to suggest we add one more next hop type in section 2.4 of > draft-ietf-i2rs-rib-data-model, and sections 2.4 & 7.2 of > draft-ietf-i2rs-rib-info-model to include a nexthop type that tells the > forwarding device to not use a particular next hop without sending traffic > to dev/null. The specific case is this -- assume I have an ECMP group with > 32 or 64 entries. In this group, I want to pin one flow to a particular set > of links, while making certain some other set of flows do _not_ use those > links. The only way to accomplish this today would be to replace every route > with the same ECMP group to provide a different set of next hops for each > one. It would be cleaner to have a construction that says, "take this next > hop out of all ECMP groups, so it is only used when specified by this > client," or some such. > > Maybe something like this in section 7.2 of the rib data model might work -- > > == > 7.4. Remove from ECMP next hop > > If the a particular route is marked "remove from ECMP," then any routes > which recurse onto this next hop as part of an ECMP group will remove any > paths using this route as a next hop from the ECMP group. This allows the > I2RS controller to remove ECMP traffic from a particular next hop to attain > finer grained control over the use of specific links to which particular > elephant flows may be pinned, or which may be otherwise congested, etc. > == > > I don't know of any implementation that could do this right now, but this > seems like a useful addition to the set of available next hops (?). > > :-) > > Russ > > > _______________________________________________ > i2rs mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/i2rs _______________________________________________ i2rs mailing list [email protected] https://www.ietf.org/mailman/listinfo/i2rs
