On 4/28/2015 10:38 AM, Tom Herbert wrote: > On Tue, Apr 28, 2015 at 10:30 AM, Joe Touch <[email protected]> wrote: >> >> >> On 4/27/2015 5:11 PM, Tom Herbert wrote: >>> On Mon, Apr 27, 2015 at 4:33 PM, Joe Touch <[email protected]> wrote: >>>> >>>> >> ... >> >>>>> 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. >> >> These should be the same bit pattern in that case. > > There are different IP protocol numbers for encapsulating IPv4 and > IPv6. 0x4 is the IP protocol for IPIP, 0x29 is the number for IPv4 > encapsulation.
Again, multiple wrongs don't make a right. Unless you handle encapsulation differently on-path, there's no reason to include that information in the header. What we ended up with for IPv4 next-header is a mess where we will continue to need to assign new numbers for all new IP-in-IP variants, instead of using the version field for EXACTLY its designed purpose. Joe _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
