On 2013-06-12 14:58, Fernando Gont wrote: > Jeroen, > > On 06/12/2013 11:44 PM, Jeroen Massar wrote: >>> with the exception of the HBH header, correct. I got tired of writing that >>> each time I was repeating myself. >>> the HBH is an issue to itself. expect those packets to be severely rate >>> limited. >> >> I am wondering why.... if your box cannot handle any headers, just >> forward the packet, decreasing the hopcount and that is just. > > Well, the router is supposed to process the HBH header.
According to the spec, yes, but does it make sense? See more below. (note that must is not written in capitols in 2460 btw ;) > And, for some > options, if the option in question is not supported, the packet should > be dropped -- i.e., you cannot just "ignore the hbh header" (at east in > theory). Why not? Is there any HBH header that is crucial for operation of IPv6? It might be in the RFC, does not mean it is actually needed ;) On 2013-06-12 15:06, Joe Touch wrote: > [..] > The only valid way to ignore the HBH header is when all its component > options are "00" - skip option if not supported. None of the variants will ever catch on/make sense unless one can do a full network upgrade to support that special option. And unless one can upgrade the whole Internet (or at least the network your packets travel over), the only useful one is ignore, the others are futile unless one wants to probe which boxes support that feature, which would thus allow fingerprinting of the age of the stack. > If you don't check that, then you don't know whether it's valid to > ignore the options. That would interfere with the semantics of options > defined as "discard" or "discard and inform". But ignoring them, allows any box that does implement the option to actually process them. If something uses the 'discard' ones, it would require the whole network to be upgraded in one go, and that is not ever going to happen. Thus either one does that upgrade or one never specifies discard and then ignoring is perfect IMHO. Greets, Jeroen (hmmm should have had this whole discussion the previous week, as then I could have asked Bob Hinden what the real intent behind all of this was upto at least this morning ;) _______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area
