[gtld-tech] Delegated nameservers RFC compliance

Francisco Arias francisco.arias at icann.org
Tue Jul 19 17:17:06 UTC 2016

Hi Mark,

Are you suggesting there is an issue with TLD servers or second-level names, or both?



On 7/18/16, 2:07 PM, "gtld-tech-bounces at icann.org on behalf of Mark Andrews" <gtld-tech-bounces at icann.org on behalf of marka at isc.org> wrote:

    As part of preparations for shipping nameservers that support DNS
    COOKIES (RFC 7873) I have been measuring EDNS Compliance in a number
    data sets the results of which are available at https://ednscomp.isc.org
    along with a online tester.  We wanted how much will break when we
    ship BIND 9.11.0 which has DNS COOKIES on by default.
    We found there were zones that could no longer resolve if validation
    was enabled. Named falls back to plain DNS on certain detected
    errors as there isn't time to probe exact failure causes by trial
    and error.  Even if trial and error worked for DNS COOKIEs the
    problem will get worse as more EDNS features get used.
    We found zones that were taking multiple seconds to resolve.  We
    were back to the sort of resolution times we saw when EDNS was first
    introduced for some zones.
    We saw increased queries being needed to be made as servers didn't
    correctly ignore unknown EDNS options.
    All these errors are easily determinable by running a handful of
    queries against each server.
    RFC 1034 and RFC 1035 were written assuming that servers delegated
    to would be RFC compliant.  Currently GTLD servers are checked and
    there is no reason that servers delegated to by the GTLD servers
    can't also be checked and the operators asked to fix the faults
    detected.  This can be done at both the RFC 1034 and RFC 1035 level
    and at the EDNS level.  It is not a actionable condition if all the
    EDNS tests fail in a way that indicated the EDNS is not supported.
    I would suggest that {E}DNS compliance checking be done within a
    week of a new server being registered and delegated to and 1/2
    yearly thereafter.  If a server fails a test that the operator /
    registrant be informed and the server be retested in a month.  I
    would also suggest that compliance testing results and test date
    should be record in whois or similar so there is no need to retest
    too frequently.
    Mark Andrews, ISC
    1 Seymour St., Dundas Valley, NSW 2117, Australia
    PHONE:	+61 2 9871 4742		         INTERNET: marka at isc.org

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