nanog mailing list archives

Re: reliably detecting the presence of a bridge?


From: Jared Mauch <jared () puck Nether net>
Date: Tue, 15 Dec 2015 08:04:36 -0500

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.


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