On Tue, 23 Feb 2016, Mark Andrews wrote:
Strictly speaking the additional section can have anything the server feels is relevent including a OPT record (this in RFC 1034). Clients are expected to cope with anything added to the additional section.
That said it is pointless to add a OPT record unless you know the client understands OPT. Using a extended rcode would also be problematic as they require that the client understand OPT records which can't be determined unless you have see a OPT in the request. Unknown EDNS options are expected to be ignored in both requests and replies so it is safe to add a unknown EDNS option to either. This actually means you can add this option to any response but I would limit it to responses where there was a OPT record in the request.
I'm fine with that change. It makes sense to me. Paul _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
