Hi Suresh, If you read the mail below (which I sent earlier in the day) this is what I had said too. Just reserving values will not do, we need to also define the structure otherwise it will not work.
> i.e. An unknown extension header will have a known "Next Header" value but > an unknown "Specific Type" inside the GIEH and an unknown upper layer > protocol will have an unknown "Next Header" value. This need not be the case. What if two new headers are defined. Also if it is a payload how do we make sure the payload first byte does not match a known "Next header" field. I think the first case you need to define is some values of extension headers (x to y). That will solve all your issues. Thanks, Vishwas On Mon, Apr 26, 2010 at 4:24 PM, Suresh Krishnan <suresh.krish...@ericsson.com> wrote: > Hi Vishwas, > > On 10-04-26 05:13 PM, Vishwas Manral wrote: >> >> Hi Stig, >> >>> I can agree that it's good to check demand, but I think it is good to >>> do the "future proofing" anyway. Things can then be implemented today >>> and work correctly (as in ignoring unknown headers and still finding >>> the transport) if new headers are introduced later. >>> >>> An alternative approach could perhaps be to set aside a small range of >>> protocol values for future extension headers? >> >> I do not think it is an alternative approach. The values tell its an >> extension header (and are required look at my previous mail) and >> follows the format defined, but the structure still needs to be >> defined. > > I think Stig means reserving a few IP protocol values for extension headers. > It is certainly an alternative approach (the scheme proposed in the draft > uses only one protocol number and demultiplexes extension headers based on > the "Specific Type" field) > > Thanks > Suresh > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
