Hi Joe, > -----Original Message----- > From: Joe Touch [mailto:[email protected]] > Sent: Thursday, February 26, 2015 3:11 PM > To: Templin, Fred L; Ronald Bonica; Carlos Pignataro (cpignata) > Cc: [email protected] > Subject: Re: [Int-area] draft-ietf-intarea-gre-ipv6 > > > > On 2/26/2015 3:00 PM, Templin, Fred L wrote: > > Hi Joe, > > > >> -----Original Message----- > >> From: Joe Touch [mailto:[email protected]] > >> Sent: Thursday, February 26, 2015 2:11 PM > >> To: Templin, Fred L; Ronald Bonica; Carlos Pignataro (cpignata) > >> Cc: [email protected] > >> Subject: Re: [Int-area] draft-ietf-intarea-gre-ipv6 > >> > >> > >> > >> On 2/25/2015 4:01 PM, Templin, Fred L wrote: > >> ... > >>> I have proposed sending PTB with MTU less than 1280 before as well: > >>> > >>> http://www.ietf.org/archive/id/draft-templin-6man-linkadapt-01.txt > >>> > >>> The idea is to enlist the original source’s aid in easing the frag/reass > >>> burdens from the tunnel ingress and egress. > >> > >> IMO, PTB is the wrong message for that. > > > > What we have today is a "Type 0" PTB message. > > There are may types for both IPv4 and IPv6. > > For IPv4, e.g., PTB is type 3, code 4. > > For IPv6, it would be type 2, code 0.
"type 2, code 0" is what I meant when I said "Type 0", yes. > > What I proposed was a "Type 1" PTB message. > > For IPv6, did you mean type 2, code 1? Yes; "type 2, code 1" is what I meant when I said "Type 1". > The problem is that legacy receivers will interpret type 2 and ignore > the code. Yes, but I do not see a problem. If the size reported in the PTB is less than 1280 the source will send subsequent messages as "atomic fragments" per Section 5 of RFC2460. The tunnel ingress will then know that it is dealing with a legacy source, and will fragment the payload packet using the fragment header conveniently provided by the source. > If you want a new kind of message that is a "soft" "too big", you'd need > to define a new type. I don't agree, since legacy sources will not be harmed and will in fact still benefit if they fail to distinguish the two message codes. Thanks - Fred [email protected] > Regardless of how it's created, you're talking about a new message, and > that's out of scope for this doc (and this thread). > > Joe _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
