On 4/23/2015 8:58 AM, Templin, Fred L wrote: ... >> Beyond suggesting that the probing mechanism use a 1280-byte payload, we >> have put the details of that probing mechanism out of >> scope for this document. > > If a 1280 byte probe (which becomes 1280+ENCAPS bytes following > encapsulation) succeeds along one path of a multipath, but would > have failed along another path, then there is possibility for black > holing. And, there is no way for the ingress to know that there > may be ECMP or LAG on the path to the egress. Hence, having the > ingress probe for the purpose of minimum MTU detection is > problematic if there may be some kind of multipath.
Probe success tells you only that. Probe loss tells you only that. IP allows loss, so strictly there's no reason to shut a tunnel down due to loss. Burst lost or patterns of loss might be undesirable, but they're allowed by IP. However, it might be useful to note that probe success isn't the only issue; that probe loss over 1% might be considered problematic (using the typical performance needed for 'reasonable' TCP progress). Joe _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
