IETF Logo Mail Archive

Re: [Ntp] Garbage NTP request packets

Daniel Franke <dfoxfranke@gmail.com> Wed, 23 September 2020 19:49 UTC

Return-Path: <dfoxfranke@gmail.com>
X-Original-To: ntp@ietfa.amsl.com
Delivered-To: ntp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 08AA93A13F8 for <ntp@ietfa.amsl.com>; Wed, 23 Sep 2020 12:49:01 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.098
X-Spam-Level:
X-Spam-Status: No, score=-2.098 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, SPF_HELO_NONE=0.001, 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 gUXgUbMNpn7b for <ntp@ietfa.amsl.com>; Wed, 23 Sep 2020 12:48:59 -0700 (PDT)
Received: from mail-il1-x130.google.com (mail-il1-x130.google.com [IPv6:2607:f8b0:4864:20::130]) (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 2046C3A13F9 for <ntp@ietf.org>; Wed, 23 Sep 2020 12:48:48 -0700 (PDT)
Received: by mail-il1-x130.google.com with SMTP id z5so169168ilq.5 for <ntp@ietf.org>; Wed, 23 Sep 2020 12:48:48 -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=n0F3mixKhuYmt5kW8J19pQj6JDSRWW9iRn25zjBgRbI=; b=ZZquUgvk6avhrFeEoVjv2zyrWYNRTtUDtUGQndqeKcdUzXCCj2I/BAAVn7KODGpdDZ n7dnUv1HcMfnxC87DTUSU6cuPc3XwXECWrEalhl61E1kTPkDZx/vatvzRIoEEoC548pS bwQIymhppWThsLb5W7di93dwLWw8tTd89bea252wJ/Jf8EF9TPBT+Zs2OInyJYeGWlRY bYlauWx8bTMFeWGkHRjENOiN3fNSJY6W5enywBuzbYghvCJBppNNy5v2ZrtPQWPvO05s PxKJZJYwq7DcQisNp7rXGoIbdVQ6iQ9L0gNEZN5YkRvJjw+VZNvFruCkmz0UZp+t+aCy Yk+w==
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=n0F3mixKhuYmt5kW8J19pQj6JDSRWW9iRn25zjBgRbI=; b=sUvB/Yj5NKBz5KddkX/gjmG8ZJbWAKsDZ0JN8umJ99Sp89k3+RyogFMFMgoWu2qe+w TCLakNCJyh3aGlIs1XAP6Xxj3KUIZ8JTvSdS2pMDI4x0e2REYOkoe3RlxfBvc/V8waJd +XmCNq2huiQZXIm16AT7Irc/tEt464DjpypPVL2MM1YPSJGuTlmD2GvuBj4dova5MJZ1 zB+OWrABeG7BgoHH6HU3N9jxdxU14kuBV/WcZwdfVTC//idPHGh3bV6/m1iECs8PiqVs EOX8bbAb5K7k/I4YyLVPrcV7JzeaU6B3bxJKVIHKirtO0BQlDmqdjrubUT8lmEgUFyM9 ky0Q==
X-Gm-Message-State: AOAM5313O3bfgCFt3x/p0ZFK0d2a+it1+X3kMEkwJ01C0J2d9GEkOoPj UnfyJ2UeOl2ahhC4Q9pcdsEM4nD0SBxGBCQofsU=
X-Google-Smtp-Source: ABdhPJyWdrVTJcrQBY4x/pUrvavsVGnmfcOKvTOTPudE6TkM7mhUGTqZX3jcNhIhhEWN9LDFPx73cJivJ6r/CdjG4ls=
X-Received: by 2002:a92:2411:: with SMTP id k17mr1153708ilk.55.1600890527280; Wed, 23 Sep 2020 12:48:47 -0700 (PDT)
MIME-Version: 1.0
References: <20200923053414.07A4940605C@ip-64-139-1-69.sjc.megapath.net> <20200923084423.GA1398053@localhost> <9340fee2-dfbd-4a40-e9a9-cedc8e6222f2@ntp.org>
In-Reply-To: <9340fee2-dfbd-4a40-e9a9-cedc8e6222f2@ntp.org>
From: Daniel Franke <dfoxfranke@gmail.com>
Date: Wed, 23 Sep 2020 15:48:36 -0400
Message-ID: <CAJm83bAeXOsKuO173Dw8YYGiUc3Qy6_xko6vPosYCOSHddDWBQ@mail.gmail.com>
To: Danny Mayer <mayer@ntp.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>, Hal Murray <hmurray@megapathdsl.net>, NTP WG <ntp@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ntp/pDg98VhkkmzT4cURLPGSqL0aLBo>
Subject: Re: [Ntp] Garbage NTP request packets
X-BeenThere: ntp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <ntp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ntp>, <mailto:ntp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ntp/>
List-Post: <mailto:ntp@ietf.org>
List-Help: <mailto:ntp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ntp>, <mailto:ntp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 23 Sep 2020 19:49:01 -0000

Danny, I agree that Hal's question is slightly off-topic for this list
but I can't think of any better forum for it. The people who should
see it are all here; I don't they're all anywhere else. Is it worth
spinning up a new list for this sort of thing? Something like an
implementation-neutral forum for NTP developers and public server
operators?

On Wed, Sep 23, 2020 at 3:35 PM Danny Mayer <mayer@ntp.org> wrote:
>
> Was there a working group question in here?
>
> On 9/23/20 4:44 AM, Miroslav Lichvar wrote:
> > On Tue, Sep 22, 2020 at 10:34:13PM -0700, Hal Murray wrote:
> >> I noticed that an error counter that was going off more than I expected, so I
> >> hacked a server to print out a few garbage requests.
> > I think that's normal. On my public servers I see all kinds of weird
> > requests.
> >
> >> Ones like this happen often enough to attract my attention.
> >>   e3000000 00000000 00000000 00000000
> >>   00000000 00000000 00000000 00000000
> >>   00000000 00000000 00000000 00000000
> >>   00000020 ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
> >>
> >> The first 3 lines look like a version 4 request.  The last line starts to look
> >> like a MAC using key 20 (hex) but the HMAC/CMAC part is 28 bytes.  I haven't
> >> setup key 20 and our code doesn't support bare MACs with a total length of 32
> >> bytes.
> > This example looks like a valid NTPv4 request to me. It's not a MAC,
> > but an extension field (type 0, length 32 octets).
> >
> > I have a script for monitoring pool.ntp.org servers that sends
> > requests like that (and others) to check various features of the
> > server like whether it can respond to an unknown extension field, what
> > implementation it is running, etc. FWIW, a server that doesn't respond
> > to a request that has an unknown extension field makes it more
> > difficult for clients to detect whether the extension field is
> > supported.
> >
>
> _______________________________________________
> ntp mailing list
> ntp@ietf.org
> https://www.ietf.org/mailman/listinfo/ntp

v2.23.0 | Report a Bug | By Email