Folks, Some comments/questions regarding the aforementioned I-D:
* Meta: As noted by Ran Atkinson, I think you should clearly state what sort of options that would not fit in the Hop-by-Hop or the Destination Options headers you think could be specified (that would warrant yet another extension header) -- Existence of this would be the motivation (or lack of) to pursue the proposal in this document. Specific comments: * Section 2 states: > The intention of the base IPv6 Specification [RFC2460] that > destination hosts not be permitted to skip unknown extension headers > continues to apply. Isn't this I-D all about allowing nodes to skip unknown headers?? * Section 2 states: > Another one is that this generic extension header conserves values in > the IPv4 protocol numbers registry. Of the top of my head, less than 25% of that space is used. And this is not going to change much (at least in the IPv4 world), as it is virtually impossible to use such packets across unmanaged NATs. * Setion 2 (2. Generic IPv6 Extension Header (GIEH) format). Why not simply enforce a TLV format? (i.e., no "Specific Type" at all) * Section 4 > 4. Exceptions > > The the Generic IPv6 extension header is generic enough that it is > suitable to use for most applications. However, it is possible that > the GIEH does not satisfy the requirements in all cases where new > extension headers are required. Hence, the existence of this > generic header does not necessarily preclude the definition of new > independent IPv6 extension headers. If this not going to be enforced for all new headers, is this worth the effort? * Section 5 (Future work) >From the PoV of a firewall, this is simple: either the traffic complies with my policy, or I block it. Put another way: if the extension header is unknown, this is the reason (other than the unknown syntax) for the firewall to block it. Thanks! Kind regards, -- Fernando Gont e-mail: ferna...@gont.com.ar || fg...@acm.org PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1 -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
