Re: [DNSOP] BCP on rrset ordering for round-robin? Also head's up on bind 9.12 bug (sorting rrsets by default)

Shumon Huque <shuque@gmail.com> Tue, 19 June 2018 19:22 UTC

Return-Path: <shuque@gmail.com>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 88307130DCA for <dnsop@ietfa.amsl.com>; Tue, 19 Jun 2018 12:22:17 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.998
X-Spam-Level:
X-Spam-Status: No, score=-1.998 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 55mxJNHgvJfl for <dnsop@ietfa.amsl.com>; Tue, 19 Jun 2018 12:22:15 -0700 (PDT)
Received: from mail-yb0-x22f.google.com (mail-yb0-x22f.google.com [IPv6:2607:f8b0:4002:c09::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 33C86130E13 for <dnsop@ietf.org>; Tue, 19 Jun 2018 12:22:15 -0700 (PDT)
Received: by mail-yb0-x22f.google.com with SMTP id e84-v6so334313ybb.0 for <dnsop@ietf.org>; Tue, 19 Jun 2018 12:22:15 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Aadai+rE8Jj8NgrUNRLoC/9cfXSLz/qvpDqMJOFru80=; b=Mg7PfeY/Z6tcbKxnEKNX2I7IcXu+GRu7SNUIFb+uh72GYrG6rKu2Yr1hVh49MOPhmP UgML1006r4mvfLKDks0c3OzwzzyNYBEgVH5ZVkxe+2JuBOF5boysk69cJQFgI/ir0bPu Dfk0A+HljjRgWKclXgoQsD4aD2NBeeVE0OCO9PXaf3nkE8p9bwnkOm6yAMmySpfosDVo 8KtlRzgrPYCU8g1n7+l4A/A0E3wCOw6DYo6qLqG2r/L2xq9Yg5yayLtduiy362EHQg/a zdG+q2dKwx8BoQb7rew5aUywm97524kmeIGxFmapy1mNRpdgeuOVjrT9GJU5AMY4Gmj6 PZ4Q==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Aadai+rE8Jj8NgrUNRLoC/9cfXSLz/qvpDqMJOFru80=; b=rTKeqjwytNUMAyO3014tanYf9Ggl/sqXiSPj258pA/QacLjNsfQcphaSD7PtI1yzCP 1bwjdsrdqH789AtrvQhpy8BCG+crwTpLXKUZ6KG0+SuirmCtjm92Wdd0mEszFmeaKjWZ tm0Qg1kuS839HMzTZUtjangTVClpYmB54YjyRbxSA8G/In63c7CwB/qcq3O5fo3idKee zL4O2tSIthvhverudCBzkTDerAO2vp5bC74E6Xcw24pkFVQOgB4PvAy63hMm1S+0mvZ2 x+5lILrVioOBn9PzSCLLfEr/HwnS8DN0GCle0JH6xOy4JTnsQlVuHb4sToTvwQ6qm619 9YXw==
X-Gm-Message-State: APt69E2eW6+l2eXM76pNWO+4W3+u7i5vrv5m0g6RW9GkZz/pJnqiVHtS 8xtcslzqJ0TQTqnRZGTL9ft5yAcpAcAHpdbTQ1c=
X-Google-Smtp-Source: ADUXVKKU7DDKti52M0xZvdFsVY0pUYFG7nQK7vDmstei3d7GEzjsQelyAhif5QVpKk3vneCPLxDUKjLfRfwXyg/CH5g=
X-Received: by 2002:a25:848d:: with SMTP id v13-v6mr8878807ybk.404.1529436134440; Tue, 19 Jun 2018 12:22:14 -0700 (PDT)
MIME-Version: 1.0
References: <CAKC-DJimMOtNCSE95kRs6Dy3dC_mxB=8O2WVA7badp8GK2ci-Q@mail.gmail.com> <20180615171231.GF1126@mx4.yitter.info> <CAHPuVdWP=DVj52diWYTHKqHBET0hFyUWvACT-VpH20iKzed-ww@mail.gmail.com> <CA+nkc8AS6+cZfi_NGT2T+FeQkQ5fKn--HQOOuusL1cYFkdKbKA@mail.gmail.com> <20180615195232.GA5926@jurassic> <CAKC-DJhRJwg7cw8iexCgq9axgjyjnQQaXP2+wD4u=sk3PtypRg@mail.gmail.com> <20180618150157.GB9377@mx4.yitter.info> <5B27EFB7.1020400@redbarn.org> <874lhzu7ae.fsf@mid.deneb.enyo.de> <CAHPuVdXiM3X3hyN14+JJEXWhSrjdepj1PwRDW07mzHmgLcHjAw@mail.gmail.com> <CAJE_bqfjGwMGLTEMp6L77RUihC9Jzkq_BcBVp=643H0RcjnkAQ@mail.gmail.com>
In-Reply-To: <CAJE_bqfjGwMGLTEMp6L77RUihC9Jzkq_BcBVp=643H0RcjnkAQ@mail.gmail.com>
From: Shumon Huque <shuque@gmail.com>
Date: Tue, 19 Jun 2018 15:22:24 -0400
Message-ID: <CAHPuVdWqqRgx4d6ZrD3k+YWBDVtc-29CFDcumaRXin4efpriAQ@mail.gmail.com>
To: 神明達哉 <jinmei@wide.ad.jp>
Cc: fw@deneb.enyo.de, "dnsop@ietf.org WG" <dnsop@ietf.org>, Paul Vixie <paul@redbarn.org>
Content-Type: multipart/alternative; boundary="000000000000800506056f039954"
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/VDVpcPrwtIqXmH7kfc-9dQCw3js>
Subject: Re: [DNSOP] BCP on rrset ordering for round-robin? Also head's up on bind 9.12 bug (sorting rrsets by default)
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.26
Precedence: list
List-Id: IETF DNSOP WG mailing list <dnsop.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dnsop>, <mailto:dnsop-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dnsop/>
List-Post: <mailto:dnsop@ietf.org>
List-Help: <mailto:dnsop-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dnsop>, <mailto:dnsop-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 19 Jun 2018 19:22:18 -0000

On Tue, Jun 19, 2018 at 2:51 PM 神明達哉 <jinmei@wide.ad.jp> wrote:

> At Mon, 18 Jun 2018 17:51:26 -0400,
> Shumon Huque <shuque@gmail.com> wrote:
>
> > Client applications delegate address sorting to name resolution functions
> > like getaddrinfo() - correct?
> >
> > Doing some quick tests of getaddrinfo() just now on a recent *NIX
> machine,
> > it appears to return addresses sorted roughly in accordance with RFC
> > 6724, but rule 9 (longest prefix match) seems to be only applied to
> > IPv6 addresses. For IPv4 addresses (using an upstream resolver
> > that randomizes the response RRset), the order returned by getaddrinfo()
> > is ever changing - I assume presented in the order received.
>
> The very original implementation of BSD getaddrinfo() conformed to the
> RFC, but FreeBSD seems to have changed the behavior a few years ago so
> rule 9 wouldn't apply to IPv4 addresses:
>
> https://github.com/freebsd/freebsd/commit/1390d13ae69089142f6c6465dbb24438f295edee
> The commit log suggests the rrset round-robin was exactly the
> motivation for the change (whether it was good or bad).
>

Very useful information. Thanks for confirming!

My tests were on a Linux machine, so apparently they did the same ..

Shumon.