On 11/4/10 6:08 AM, V, Raman K (MCBS-UPEL) wrote: > Hi All, This is a question about the correct interpretation of > RFC3879. Conformance to this RFC is a requisite for USGv6/DISRv3 > certification, so I am trying to figure out the right thing to do > inside our IPv6 stack. > > A portion of Section 4 of this RFC (the crux, really) is reproduced > below: > > This document formally deprecates the IPv6 site-local unicast prefix > defined in [RFC3513], i.e., 1111111011 binary or FEC0::/10. The > special behavior of this prefix MUST no longer be supported in new > implementations. The prefix MUST NOT be reassigned for other use > except by a future IETF standards action. Future versions of the > addressing architecture [RFC3513] will include this information. >
When I maintained an IPv6 stack, I simply removed any of the special handling necessary for FEC0::/10 and treated it as any other global IPv6 prefix. For example, I removed all of the scope zone checks that are defined for scoped addresses (RFC 4007). > It seems to clearly say that an IPv6 stack must no longer support > site-local addresses, to be able to conform this RFC. So, would I be > right in assuming that our stack should simply drop the support for > site-local addresses? Or should I put more emphasis on the words "new > implementations" and say that mine isn't a new implementations (we > have had our IPv6 stack in the market for a while), so we should > continue to support site-local addresses? I would suggest dropping support. > > We are going for a USGv6 certification and knowing the right thing to > do from this expert community would very helpful. Any thoughts in > this area or any pointers in this regard would be greatly > appreciated. If you are aiming for USGv6 certification and knowing how long equipment is kept in such environments, I would lean towards playing it safe and removing any special handling for the site-local prefix. Otherwise, you run the risk that someone may put your product in a network where, years later, they start using FEC0:: in a non-site-local context. Regards, Brian -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
