[124236] in North American Network Operators' Group
Re: Auto MDI/MDI-X + conference rooms + bored == loop
daemon@ATHENA.MIT.EDU (Chuck Anderson)
Fri Mar 26 19:36:56 2010
Date: Fri, 26 Mar 2010 19:36:08 -0400
From: Chuck Anderson <cra@WPI.EDU>
To: nanog@nanog.org
Mail-Followup-To: nanog@nanog.org
In-Reply-To: <39183BDC-67DB-4523-9C3A-A80215962D3D@delong.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Fri, Mar 26, 2010 at 03:33:56PM -0700, Owen DeLong wrote:
> Switches that support STP?
Yes, "soho" or "desktop" switches I mean. Apparently Netgear GS105's
do not do STP at all, at least they don't claim to.
> There are switches that have STP protection such that they are
> portfast until they see an inbound BPDU and then revert to
> spanning tree on that port (it blocks, listens, learns, then
> forwards if appropriate).
Do the ports so configured also send BPDUs such that a loop on a
"desktop" switch uplinked to that port will cause the port to see its
own BPDUs and revert to STP Blocking? Even if that is the case, I
think the detection of BPDU and subsequent transition to Blocking will
happen too slowly. By then the damage is already done upstream in the
collapsed L2/L3 core.
