On Thu, Mar 01, 2018 at 09:52:37AM +0900, Randy Bush wrote: > question for ops: > > did you even know this was happening, that "set community" might not > replace ALL well known communities?" > > the reasom i ask is, as you see in the draft, we are hesitant to > propose changing behavior for existing wks as it might impact ops. > but if we were not aware of this behavior, then maybe change is ok, in > fact desirable. > > i did not realize this was going on. jay, who discovered it, was > surprised.
NTT noticed this type of inconsistency between some vendors somewhere in July 2016. A customer used a combination of NTT-specific BGP communities to influence traffic, together with NO_ADVERTISE. Unbeknownst to us, this combination of communities resulted in network behavior that made the customer happy. Further down the timeline, the customer was migrated to another vendor's routing platform (or got a new circuit on a new platform, don't recall) and suddenly noticed that the previously working combinatory trick no longer worked. At that point investigation showed that "set community" does not do the same thing on all platforms, and we had to figure out a way to make things consistent. Our currently routing policy is to allow (not delete) some of the well-known communities, and squash (remove) a bunch of not-so-well-know communities and unsupported well-known communities, and let potential-future-well-known communitie pass-through to try to not stiffle innovation. For each new well-known community we'll have to decide whether to remove it or let it pass-through. Kind regards, Job _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
