Hi Joe, > -----Original Message----- > From: Joe Touch [mailto:[email protected]] > Sent: Tuesday, April 28, 2015 10:29 AM > To: Templin, Fred L; Tom Herbert > Cc: [email protected] > Subject: Re: [Int-area] Why combine IP-in-UDP with GUE? > > > > On 4/28/2015 10:13 AM, Templin, Fred L wrote: > > Hi Tom, > > ... > >>>> Without any optional fields or flags, the difference with GUE is an > >>>> additional four byte header between the UDP header and the > >>>> encapsulated IP header. For IPv4 that header is 0x00040000, and for > >>>> IPv6 the header is 0x00290000 > > ... > > This loops back again to whether the first four bits of the payload could > > be used such as: > > > > 4 - a native IPv4 packet > > 6 - a native IPv6 packet > > X - a GUE-encapsulated packet > > It loops back to what the service is. > > Encapsulation of IP is a service. > > There is no justification for differentiating between encapsulation of > IPv4 and IPv6 at the GUE or IP-in-UDP layer. > > Nothing on the path should need to see what kind of IP packet it is. If > it does, it can easily parse the first for bits of the IP-in-UDP or GUE > payload - NOT the UDP payload.
What I mean to say is "the first four bits immediately following the UDP header". At least, that is what IP-in-UDP and AERO say. Were you thinking there would be some other four bits? Thanks - Fred [email protected] > Bits in the UDP payload to differentiate between IPv4 and IPv6 repeat > the many mistakes of the past and should be avoided. > > Joe _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
