[Tfug] Switch problem

[Bexley Hall]

Hi Erich,

On 3/11/2013 10:51 PM, erich wrote:
> I bought
>
> a Trendnet TEG-S80g switch, and installed it in my network. I pro-
> ceded to be amazed at the speedup.

<grin>  There was a time when "velocitized" only applied to driving!

> I'm just a home user, and turn
> everything off at nite including the switch.

I leave my fabric powered up as I never know <when> I'm going to
want to use <what>.

> The next day troubles started when I powered up my system.
> One of my boxes waited for a DHCP address that never showed
> up. Tried pinging other boxen with disturbing "address unreachable"
> messages. It was a struggle to preserve my sanity. For a while
> it seemed that the switch had damaged the network interface of
> some of my PC's. I took the new switch out of the system.
>
> After rebooting several machines, the system started coming
> back up. "Damaged" network interfaces started working again.

To be clear:  they are working with some *other* (non-Gb) switch (?)

> This is a high-speed switch. Is it possible that It could interact
> with a network interface on a box and pull it into a state that
> would remain on poweroff?

Gb interfaces have to autonegotiate lots of configuration parameters.
Among them, speed (10/100/1000), Full Dupled/Half Duplex, and usually
AutoMDIX.

I've encountered SOHO switches that wouldn't talk to other *identical*
(same manufacturer/model number) switches in the past because they
couldn't agree on a common configuration!

There are also some differences in the way vendors have chosen to
implement the Standard which can lead to... "frustration" (to put
it in practical terms  :> ).

In the past, I've resorted to manually configuring the interfaces
on the various hosts -- just to take one more set of variables out
of the equation (it also *seems* like this brings the interface up,
quicker?).

[You/I shouldn't *have* to do this but I have more fun things to
work on than screwing around with what should effectively be a
virtual *wire*!]

You can also look at your cables to make sure they aren't a part
of the problem.  A lot of this stuff is BFM and you'll find that
"a wire is not always a wire".  <frown>  Or, that a 6 ft wire
is different than a 25 ft wire!

To help with your troubleshooting, get out a pad of paper and
make notes of what you are doing, what order, and the results
you obtain.  Helps improve reproducibility if you know *you*
aren't a variable.

E.g., you might notice that plugging a cable *after* the switch
is powered gives you different results than doing so *before*
(as well as whether or not the host on the other end happens to
have brought up its interface, already).

Cheap things to try are bringing interfaces down and back up,
manually configuring them, replacing cables, etc.

Good luck!  As I say, I wimped out and just forced things to
run the way I wanted them to run...  :-/