Re: [DNSOP] I-D Action: draft-song-dnsop-tcp-primingexchange-00.txt

In message <FFAC9976-D502-4AAE-AB7D-8A869CB140AB@vpnc.org>, Paul Hoffman writes
:
> On Nov 26, 2014, at 11:18 AM, Davey Song <songlinjian@gmail.com> wrote:
> > Hi folks, I just post a draft on Priming Exchange over TCP. Comments are we
> lcome!
> 
> The proposed solution is not needed as long as the resolver that using the pr
> iming exchange can fall back to TCP. A different approach to the document wou
> ld be:
> 
>    Motivation: The root zone is longer than 512 octets,
>    so responses to priming queries are truncated.
> 
>    Requirement: All resolvers that perform priming
>    queries MUST be able to use TCP as specified in
>    RFC 1035 when performing the priming query.
> 
> That should be an RFC of less than two pages, and would not involve making pr
> iming queries special enough to require a protocol change for them.
> 
> --Paul Hoffman
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Additionally you may as well just implement EDNS.  The IPv6 response
won't be fragmented as it is < 1280 bytes and the IPv4 response is
unlikely to be fragmented as it is < 1500 bytes.  If you are making
DNS queries over IPv6 you are already required to support EDNS as
it is a node requirement.

All the root servers support EDNS as that is a prerequisite for
DNSSEC and if the firewall in front of your recursive server doesn't
it needs to be replaced if it can't support a 15 year old extension
to the protocol.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org