Le 12 août 2010 à 04:02, Brian E Carpenter a écrit : > On 2010-08-12 11:34, Philip Levis wrote: >> On Aug 10, 2010, at 11:12 PM, Rémi Després wrote: >> >>> Le 10 août 2010 à 18:09, Michael Richardson a écrit : >>> >>>>>>>>> "Rémi" == Rémi Després <remi.desp...@free.fr> writes: >>>> Rémi> RFC 3697 isn't concerned with ASes, and doesn't need to be. >>>> Rémi> The proposal is only that, where load balancing is performed, >>>> Rémi> 0 FLs MAY be replaced by meaningful values for this purpose. >>>> Rémi> A FL, once set to a non 0 value, never needs to be reset. >>>> >>>> okay, so what you are saying is that load balancing uses of the FL are >>>> only upset when they see zero. So for instance, if layer-4s (i.e. end >>>> points) were mandated that they must now always set a FL consistently on >>>> a flow, and set it to a non-zero value, that this would satisfy the >>>> requirements of load balancers. >>> Right. >>> >>> To be even more precise: >>> - Flow endpoints (sometimes layer 4 and sometimes layer 3) should from now >>> on be mandated to set FLs with non-0 values that statistically differ from >>> a flow to another. >> >> The intention is to have a BCP for network stack implementers to follow? > > I don't there is a clear intention just yet, but my personal view is coming > round to a 3697bis document, which would presumably be Proposed Standard, > not BCP.
+1 > But certainly we need more precise normative guidance. Yes. RD > >> >> >>> - However, we have to face that, so far, they are generally mandated to set >>> FLs to 0. >> >> I apologize for the lack of context (I'm coming from ROLL): your sentence >> seems to suggest that flow labels today are mandated to be 0. This doesn't >> seem to be right: among other things, ping6 supports setting the flow label, >> and by default allocates a random flow label.[1] Basically, I'm confused if >> you're talking in the present tense of what's done with flow labels today, >> or the future tense of how flow labels should be used in the future. > > What 3697 says is > "A Flow Label of zero is used to indicate packets not part > of any flow. > ... > A source node which does not assign traffic to flows MUST set > the Flow Label to zero." > > It's a little self-referential, since flow *by definition* is > a set of packets with the same flow label (and address pair). > The rule is there to prevent accidental flow labels because > the programmer simply forgot to zero the field. > > That being so, it isn't clear to me that we need a mandatory > flow label, although I can make some arguments for a SHOULD. > > Brian > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
