Re: [Doh] Dedicated DoH port

Erik Nygren <erik+ietf@nygren.org> Thu, 11 April 2019 17:56 UTC

Return-Path: <nygren@gmail.com>
X-Original-To: doh@ietfa.amsl.com
Delivered-To: doh@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5448F1206C6 for <doh@ietfa.amsl.com>; Thu, 11 Apr 2019 10:56:32 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.647
X-Spam-Level:
X-Spam-Status: No, score=-1.647 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
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 gcb_sqnsK0EI for <doh@ietfa.amsl.com>; Thu, 11 Apr 2019 10:56:30 -0700 (PDT)
Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) (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 6F460120683 for <doh@ietf.org>; Thu, 11 Apr 2019 10:56:30 -0700 (PDT)
Received: by mail-wr1-f46.google.com with SMTP id y7so8494542wrn.11 for <doh@ietf.org>; Thu, 11 Apr 2019 10:56:30 -0700 (PDT)
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=Mz9qicHi52P3gg14SvdGoiKIbHTl+Kl3mtgx6JQx8Xs=; b=XWIjnUPtB7ad3/aYCC+SgXboO1pplM9T/z+AcJovZjQwVHNR7Y+WNFgbE4Hn+b7uSw JuN7/guCHb4hhCsulJ56kjgrLfHQjCRFlVIXk+/aqit1VTdR8SaCLDyymPOF7DIfctKH JNRUCpJAoxIEgupZLmBbP+kI2yzUmKxTHmcwO2fzL40VleNcg/ftfe6UBFX+t/vvut9q vAvUIOtN/IeGAs9NcIW0q5WIwhzRKeoANYG/r5DqIxx3mhpCKb3LXuTJR0u17WOCNI14 3Pgy2y77yZdDbuzUDjxaxfetEt/KNiHGivxH7z7bntv9tq+Qp4XEPHGi7syGGrWx35Jt KhvQ==
X-Gm-Message-State: APjAAAUPioFStbZFiljWOzwu9QPHBSatbh9F7ZSSzES+GbavMyfttXJh C259v7oKpSXjY5oX/J/Jqd1nwTrJrwTVk/D8lRS9q9Pj
X-Google-Smtp-Source: APXvYqwAfytJDUjwYVjYljwfznN2fXIYmPI5PN2klnu7Lku7hAABN+9KKxnUqIDTY9FaZrdWYPzjKPnY3TYOk7V1Sy8=
X-Received: by 2002:adf:f48d:: with SMTP id l13mr27326145wro.2.1555005388542; Thu, 11 Apr 2019 10:56:28 -0700 (PDT)
MIME-Version: 1.0
References: <d74add8f-8964-1c0f-cd2e-f10867390883@nic.cz>
In-Reply-To: <d74add8f-8964-1c0f-cd2e-f10867390883@nic.cz>
From: Erik Nygren <erik+ietf@nygren.org>
Date: Thu, 11 Apr 2019 13:56:16 -0400
Message-ID: <CAKC-DJg0dv7xYHUHrnd+n9hjnhueZhzybHn3=i7G+f3rL=z7Cg@mail.gmail.com>
To: Tomas Krizek <tomas.krizek@nic.cz>
Cc: DoH WG <doh@ietf.org>
Content-Type: multipart/alternative; boundary="000000000000ced85e058644e7cd"
Archived-At: <https://mailarchive.ietf.org/arch/msg/doh/zoVqgABtfHTZKVpx1ZGaNOm70A4>
Subject: Re: [Doh] Dedicated DoH port
X-BeenThere: doh@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DNS Over HTTPS <doh.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/doh>, <mailto:doh-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/doh/>
List-Post: <mailto:doh@ietf.org>
List-Help: <mailto:doh-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/doh>, <mailto:doh-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 11 Apr 2019 17:56:33 -0000

Would it make more sense to request something out of the well-known ports
range,
or at least outside of commonly-used ephemeral port ranges?

       Erik


On Thu, Apr 11, 2019 at 1:41 PM Tomas Krizek <tomas.krizek@nic.cz> wrote:

> Disclaimer: I don't adocate the use of a dedicated DoH port rather than
> using port 443 for most DoH traffic. I'm simply trying to establish
> reasonable defaults as a software developer and packager.
>
> Knot Resolver will use 44353 as the default port for DoH. We've
> considered using port 443 by default, but it presents many challenges.
>
> If an admin is already running an https service on the machine, the
> clash with DoH resolver can be quite problematic. In best case scenario,
> the admin runs into an error (not able to bind to port 443 - quite
> cryptical for someone trying to run DNS resolver who's not up to date
> about DoH development). In a worse case scenario, the DoH service might
> actually seem to successfully start and run alongside the unrelated
> https service (e.g. when both services use systemd socket activation
> with ReusePort=true - basically SO_REUSEPORT under systemd).
>
> Those who know what they're doing will have no issues configuring their
> DoH service to run on port 443. However, I think it's reasonable to use
> a different, dedicated port as DoH default for packaging, documentation
> etc.
>
> Since there is currently no IANA assigned DoH port, I've filed the
> following user port request with IANA to establish a common default that
> could be used among DNS vendors.
>
> Service Name:         [domain-doh]
> Desired Port Number:  [44353]
> Description:          [DNS query-response protocol over HTTPS]
> --
> Tomas Krizek
> PGP: 4A8B A48C 2AED 933B D495  C509 A1FB A5F7 EF8C 4869
>
> _______________________________________________
> Doh mailing list
> Doh@ietf.org
> https://www.ietf.org/mailman/listinfo/doh
>