On 02/02/2017 09:26 PM, Brian E Carpenter wrote: > > On 02/02/2017 22:14, Fernando Gont wrote: > ... >> The current impossibility to parse an IPv6 header chain that includes >> unknown Next Header values > > Wait... you're talking about parsing by intermediate systems. The destination > node either can understand the new Next Header or transport protocol, > or it can't. That's fine, and is the intended result. If it can, it already knows the syntax, so what's the point of a uniform syntax? -- it could be anything, and wouldn't change anything. >> results in concrete implications for the >> extensibility of the IPv6 protocol, and the deployability of new >> transport protocols. Namely, >> >> o New IPv6 extension headers cannot be incrementally deployed. >> >> o New transport protocols cannot be incrementally deployed. > > In both cases, add "in the presence of interfering middleboxes". > > This is not new. For a document moving from PS to Standard, it is > not something we can change. > > Note, I am all for coming back to this problem, after we have the > Internet Standard in place. Maybe we can fix it or maybe we can't, > but it's IMHO off topic here. Ok. Makes sense. Cheers, -- Fernando Gont SI6 Networks e-mail: fgont@xxxxxxxxxxxxxxx PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492