[Tfug] Switch problem

[erich]

Yes,
         I've isolated my switch. I have it mediating between two boxen at
a time and discovered some interesting properties

           1)  The little switch will tell you the capabilities of your 
box's
interface card, 10/20Mbps, 100/200Mbps, and 2000Mbps

           2) The problem shows up if everything is unplugged from
power lines. In other words we're not even using stand-by pwer
supplies, and the switch power supply was unplugged, (This
is unusual. Network gear usually runs 24-7)

           3) Old, slow boxen have the most trouble: It's not
enough to reboot this old slow box of mine. I had to
shut it down, Power it off, and bring it back up again
before it finally started working networkwise.

           4) If the switch is not shut down. Other boxen will
recover and work normally when powered up with
their network interfaces. (I hope this is true. I've not
tested this proposition with my entire network). The
little switch uses 3.5 watts. So leaving it run 24-7
won't brake ta bank.

Erich


Bexley Hall wrote:
> 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...  :-/
>
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