and IPv6

Thu Nov 17 02:10:16 UTC 2016

I think it is not just a matter of testing behind a 1280 MTU, but about making sure that PMTUD is not broken, so it just works in any circumstances.


-----Mensaje original-----
De: NANOG <nanog-bounces at> en nombre de Mark Andrews <marka at>
Responder a: <marka at>
Fecha: jueves, 17 de noviembre de 2016, 9:26
Para: Lee <ler762 at>
CC: <nanog at>
Asunto: Re: and IPv6

    In message <CAD8GWsvetSmn1ssFk_AdTtKheog0e1ZfXRLd11FpkbPJGHM6hw at>
    , Lee writes:
    > On 11/16/16, Mark Andrews <marka at> wrote:
    > >
    > > In message <1479249003.3937.6.camel at>, Carl Byington
    > > writes
    > > :
    > >> -----BEGIN PGP SIGNED MESSAGE-----
    > >> Hash: SHA512
    > >>
    > >> Following up on a two year old thread, one of my clients just hit this
    > >> problem. The failure is not that is not reachable over ipv6
    > >> (2605:3100:fffd:100::15). They accept (TCP handshake) the port 443
    > >> connection, but the connection then hangs waiting for the TLS handshake.
    > >>
    > >> openssl s_client -connect
    > >>
    > >> openssl s_client -servername -connect
    > >>
    > >> Browsers (at least firefox) see that as a very slow site, and it does
    > >> not trigger their happy eyeballs fast failover to ipv4.
    > >
    > > Happy eyeballs is about making the connection not whether TCP
    > > connections work after the initial packet exchange.
    > >
    > > I would send a physical letter to the relevent Inspector General
    > > requesting that they ensure all web sites under their juristiction
    > > that are supposed to be reachable from the public net get audited
    > > regularly to ensure that IPv6 connections work from public IP space.
    > That will absolutely work.
    > NIST is still monitoring ipv6 .gov sites
    Which show green which means that the tests they are doing are not
    sufficient.  They need to test from behind a 1280 mtu link.
    The DNSSEC testing is also insufficient. shows
    green for example but if you use DNS COOKIES (which BIND 9.10.4 and
    BIND 9.11.0 do) then servers barf and return BADVERS and validation
    fails.  QWEST you have been informed of this already.
    Why the hell should validating resolver have to work around the
    crap you guys are using?  DO YOUR JOBS which is to use RFC COMPLIANT
    servers.  You get PAID to do DNS because people think you are
    compentent to do the job.  Evidence shows otherwise. show the broken
    servers for .gov.  It isn't hard to check.
    > so the IG isn't going to do anything there & has a contact us page
    > that I'd bet works much better than a letter to the IG
    You have to be able to get to to use
    it.  Most people don't have the skill set to force the use of IPv4.
    If it is production it should work.  It is the I-G's role to ensure this
    happens.  Butts need to kicked.
    > Regards,
    > Lee
    Mark Andrews, ISC
    1 Seymour St., Dundas Valley, NSW 2117, Australia
    PHONE: +61 2 9871 4742                 INTERNET: marka at

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