Strange Problem - Win2k Laptops randomly drop network connection

[Mark Tewkesbury]

Hi all,

I desperately need some help. I have a strange problem whereby 3 of my
Win2k Thinkpad A21m laptops on a medium sized (300 users) network
randomly drop their tcpip connection. I have tried re-installing the
network drivers, changing IP addresses (we use static network) and
checking hubs and cabling. Also tried disabling/enabling the active
network connection.

The only thing that works is to take the laptop from the user's
workstation directly into the wiring closet and connecting directly to
a port on the hub. Bingo, the network connection picks back up again
and everything is fine. I take the laptop back to the user's
workstation, re-connect to the network drop there and everything is
fine until the next time.

I cannot for the life of me explain: a) why causes the problem and b)
why connecting directly to the hub fixes the problem. As I said I have
replaced cabling, changed hub ports and nothing works. The problem
keeps coming back once every few weeks.

Any help would be greatly appreciated,

Mark

 

[Herb Martin]

I desperately need some help. I have a strange problem whereby 3 of my

Win2k Thinkpad A21m laptops on a medium sized (300 users) network
randomly drop their tcpip connection. I have tried re-installing the
network drivers, changing IP addresses (we use static network) and
checking hubs and cabling. Also tried disabling/enabling the active
network connection.

You aren't likely to get much help unless you describe precisely what
happens.

"Drop network connection" is pretty vague -- especially when troubleshooting
a "weird" problem.

You are going to have to get VERY LITERAL and VERY PICKY
to solve most such (weird) problems.

The only thing that works is to take the laptop from the user's
workstation directly into the wiring closet and connecting directly to
a port on the hub.

Sounds like bad cables and/or bad network hub.

Is this an intellegent hub that locks out machines ports
with some error threshhold?

Is the hub managed? SNMP?

I cannot for the life of me explain: a) why causes the problem and b)
why connecting directly to the hub fixes the problem. As I said I have
replaced cabling, changed hub ports and nothing works. The problem
keeps coming back once every few weeks.

Most likely -- first guess, would be that unplugging from the hub
is reseting it's error counter. I would look to the hub first for the
reason it "works and stops spontaneously" but the CABLE for
as the most likely PRIMARY cause.

Drop cables are notoriously bad and notoriously overlooked when
troubleshooting.