Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!feeder.news-service.com!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <rosuav@gmail.com>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.017
X-Spam-Evidence: '*H*': 0.97; '*S*': 0.00; 'wed,': 0.04; 'system?': 0.07; 'confuse': 0.09; 'sockets': 0.09; 'subject:Problem': 0.09; 'tcp/ip': 0.09; 'somewhere': 0.11; 'am,': 0.14; 'say,': 0.14; 'skip:f 30': 0.14; 'wrote:': 0.14; 'eternal': 0.16; 'packet': 0.16; 'protocol': 0.16; 'stack': 0.16; 'obviously': 0.20; 'seems': 0.21; 'header:In-Reply-To:1': 0.22; 'trying': 0.23; 'received:209.85.214.174': 0.23; 'received:mail- iw0-f174.google.com': 0.23; 'replacing': 0.23; '\xa0if': 0.23; '(e.g.': 0.26; "i'm": 0.26; 'proprietary': 0.26; 'chris': 0.27; 'message-id:@mail.gmail.com': 0.28; 'remote': 0.28; 'do.': 0.31; 'humans': 0.31; 'it.': 0.31; 'to:addr:python-list': 0.32; 'done': 0.32; 'implemented': 0.33; 'connection': 0.33; "isn't": 0.34; 'using': 0.34; 'getting': 0.36; 'else': 0.37; 'data': 0.37; 'two': 0.37; 'raw': 0.37; 'received:209.85': 0.37; 'exactly': 0.37; '20,': 0.38; 'apr': 0.38; 'received:google.com': 0.38; 'but': 0.38; 'cut': 0.39; 'received:209.85.214': 0.39; 'likely': 0.39; 'to:addr:python.org': 0.39; 'received:209': 0.39; 'would': 0.40; "it's": 0.40; 'header:Received:5': 0.40; 'address': 0.61; 'skip:1 10': 0.62; '2011': 0.62; 'full': 0.62; 'receive': 0.68; 'broadcast': 0.68; '(non': 0.84; 'make,': 0.84; '10:00': 0.91; 'edwards': 0.91; 'involved.': 0.91; 'presumably': 0.91
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type:content-transfer-encoding; bh=65nR0aE8+Mjq2YJ1is1A4hFgIVQElqw0z82tz5Plg3c=; b=DcrsO3WqecHORJvx75RyUsCH9yyaf7nvxlkRQdSvN2qWFuVX3/tR+xo3YY+oi2ewny BX8Ep1GKxku8QvblD1Sg5BQ+H6KrET9uXAZCV5sEuUSMPiiHfhMu6Xnr6tiFbCV7kGfG gMLvarTmUL8x1CNu3GHDupEt4eK+MA8I6cqXM=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=nnk0ylkxK7y8UsHTZueALGdtNKGThBshP/b6efs8NYXc3PYyUsPdcKMguzml1bowiG R6AYXe2RniodxiXfevbGsadqVh2BzA8+wrZC87tKRQGDIfwvMucOifP2zhmdU40FoPtP Ux4jTBjrPbeJdbMVDoMUWsWp8EC39sfS7Ua0U=
MIME-Version: 1.0
In-Reply-To: <iol7no$ah2$2@reader1.panix.com>
References: <iol1tv$8dn$1@reader1.panix.com> <mailman.590.1303256405.9059.python-list@python.org> <iol7no$ah2$2@reader1.panix.com>
Date: Wed, 20 Apr 2011 10:32:02 +1000
Subject: Re: Problem receiving UDP broadcast packets.
From: Chris Angelico <rosuav@gmail.com>
To: python-list@python.org
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.594.1303259529.9059.python-list@python.org>
Lines: 24
NNTP-Posting-Host: 82.94.164.166
X-Trace: 1303259529 news.xs4all.nl 81475 [::ffff:82.94.164.166]:60071
X-Complaints-To: abuse@xs4all.nl
Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:3619

On Wed, Apr 20, 2011 at 10:00 AM, Grant Edwards <invalid@invalid.invalid> w=
rote:
> If I send a packet to ff:ff:ff:ff:ff:ff--255.255.255.255, it's because
> I want everybody on the Ethernet segment to receive it. =A0If I wanted
> only people on a particular subnet (e.g. 10.0.0.0/8) to receive it, I
> would have sent it to the subnet broadcast address (e.g. 10.255.255.255).

> It seems I'm going to have to use raw sockets to do what I need to do.
> That's exactly what I was trying to avoid by using UDP: I'm replacing
> a proprietary (non IP) MAC-level protocol that was implemented using
> raw sockets.

I have to ask:

1) Why do you have two subnets on the same switch? Isn't that going to
be an eternal maintenance headache? Not that it _can't_ be done -
obviously it can - but it's likely to confuse the humans involved.

2) Can you replace that protocol at a higher level? Presumably there's
a full protocol stack with application data getting wrapped up inside
(ultimately) ethernet frames; can you cut it somewhere else and make,
say, a TCP/IP connection to the remote system?

Chris Angelico