Le 10 août 2010 à 18:09, Michael Richardson a écrit : > >>>>>> "Rémi" == Rémi Després <[email protected]> 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. - However, we have to face that, so far, they are generally mandated to set FLs to 0. - To mitigate the negative effect of this fact on uses of FLs as heuristic flow discriminants, intermediate nodes may replace 0 values by values that statistically differ from a flow to another. Note also that intermediate nodes typically don't reassemble multi-packet datagrams. In this common case, they can only identify the IPv6 flow of a packet based on its two addresses and its next header. Setting the FL with a hash of this ID is still useful for downstream nodes to be able to use it (rather than treating the packet as if in the carryall set of 0-FL packets, or having to recompute its flow ID). Regards, RD > > In this context, permission would be given to set zero FL to a non-zero > value. > > -- > ] He who is tired of Weird Al is tired of life! | firewalls > [ > ] Michael Richardson, Sandelman Software Works, Ottawa, ON |net > architect[ > ] [email protected] http://www.sandelman.ottawa.on.ca/ |device > driver[ > Kyoto Plus: watch the video <http://www.youtube.com/watch?v=kzx1ycLXQSE> > then sign the petition. -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
