[TriLUG] Slightly OT: network switch question

[David Brain via TriLUG]

Port speed (re)negotiation problems?  That would explain the
disconnect/reconnect fix.


On Tue, May 15, 2018, 5:37 PM Matt Flyer via TriLUG <trilug at trilug.org>
wrote:

> Mike,
>
> Thank you for the reply.  Good information.
>
> In this case it is a static IP address so it isn't a lease question.
>
> Some more information that may be pertinent.  Ping to the remote end of
> the bridge shows "Host network unreachable" (I think it was) and ARP is
> showing 'incomplete'.  It is all on the same LAN segment but there are
> switches and what not in between.
>
> The lights on the switch were hard to see but it looks like the
> connection light (green) was light and the yellow activity light was
> blinking, but slower than expected.  It is almost as if the device or
> port had gone to a non configured state or something.
>
>
> On Tue, 2018-05-15 at 17:22 -0400, Mike Lisanke wrote:
> > Just a thought, but if one or both routers are connected as Dynamic
> > IP to upstream... then on may have missed its lease renewal and
> > removing+restoring the Ethernet cable would have been detected and
> > new lease request issued resolving a problem... for Static IP
> > assignment, that wouldn't apply. I've had cascaded routers loose
> > their Dynamic but assigned IP and reboot/reconnect resolves the
> > problem... I never looked closer as to why the lease was allowed to
> > expire without proper renewal.
> >
> > On Tue, May 15, 2018 at 3:00 PM, Matt Flyer via TriLUG <trilug at trilug
> > .org> wrote:
> > > I have an application that uses two wireless modems, running Linux
> > > as
> > > their OS, as a wireless Ethernet bridge.  The devices have been up
> > > for
> > > a little over 5 years without issue until about six months ago when
> > > the
> > > link stopped working.  At the time, removing and reinserting the
> > > network cable between the main building network switch and one of
> > > the
> > > modems got things working again.
> > >
> > > Last Saturday they stopped communicating again.  I did a reset of
> > > both
> > > of the wireless modems.  In one case, I pulled the POE / Ethernet
> > > cable
> > > out of the modem performing a power reset on it.  Similarly on the
> > > other modem, I performed a power reset by pulling the AC plug on
> > > the
> > > POE injector as the modem is physically inaccessible without a lift
> > > /
> > > bucket truck.  This had no effect and did not solve the problem.
> > >
> > > I was reviewing some documentation on the previous failure and
> > > noticed
> > > that it got 'fixed' when someone pulled the Ethernet cable between
> > > the
> > > building switch and the POE injector.  This would have interrupted
> > > the
> > > communications, but not power reset the wireless modem.  It would
> > > have
> > > also broken the physical connection as far as the building switch
> > > was
> > > concerned.
> > >
> > > My question is, what happens at the switch when you pull the
> > > network
> > > cable and break the circuit?  More importantly, what happens that
> > > could
> > > have caused things to 'reset'? I am starting to think that this is
> > > a
> > > switch problem and not an issue with the wireless modem, which is
> > > what
> > > I had initially assumed.
> > >
> > > My knowledge of Ethernet doesn't go down to the physical level, so
> > > I
> > > thought I would throw this question out in the hopes that someone
> > > has
> > > an idea.
> > >
> > >
> > >
> > > --
> > > This message was sent to: Mike Lisanke <mike.lisanke+trilug at gmail.c
> > > om>
> > > To unsubscribe, send a blank message to trilug-leave at trilug.org
> > > from that address.
> > > TriLUG mailing list : https://www.trilug.org/mailman/listinfo/trilu
> > > g
> > > Unsubscribe or edit options on the web  : https://www.trilug.org/ma
> > > ilman/options/trilug/mike.lisanke%2Btrilug%40gmail.com
> > > Welcome to TriLUG: https://trilug.org/welcome
> >
> >
> --
> This message was sent to: dbrain at gmail.com <dbrain at gmail.com>
> To unsubscribe, send a blank message to trilug-leave at trilug.org from that
> address.
> TriLUG mailing list : https://www.trilug.org/mailman/listinfo/trilug
> Unsubscribe or edit options on the web  :
> https://www.trilug.org/mailman/options/trilug/dbrain%40gmail.com
> Welcome to TriLUG: https://trilug.org/welcome