[186383] in North American Network Operators' Group
Re: reliably detecting the presence of a bridge?
daemon@ATHENA.MIT.EDU (Jared Mauch)
Tue Dec 15 08:04:44 2015
X-Original-To: nanog@nanog.org
Date: Tue, 15 Dec 2015 08:04:36 -0500
From: Jared Mauch <jared@puck.Nether.net>
To: Dave Taht <dave.taht@gmail.com>
In-Reply-To: <CAA93jw6LXBpSfXcF2PgqrLjQ53bOdwXErHZNpjMpmEJ-N7FKVw@mail.gmail.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Tue, Dec 15, 2015 at 10:48:50AM +0100, Dave Taht wrote:
> I am curious if there is some sort of igmp or other form of message
> that would reliably detect if a switch had a bridge on it. How could
> deviceA detect deviceC was a bridge in this case?
>
> deviceA -> ethernet switch -> deviceB
> ethernet switch -> deviceC with bridged wifi and ethernet
>
> question came up in the context of:
>
> http://lists.alioth.debian.org/pipermail/babel-users/2015-December/002231.html
The best way I've seen is to measure latency to the devices and infer from there.
You can always make the latency longer, but making it shorter is much harder :)
- Jared
--
Jared Mauch | pgp key available via finger from jared@puck.nether.net
clue++; | http://puck.nether.net/~jared/ My statements are only mine.
