Continual Network Disconnecting/Reconnecting

I have a group of PCs running WinXP Pro. They have all been running fine for
about 6 months, but in the last several days all of them go through phases
during the day where every 1 sec it reports a network disconnected and then
1 sec later a network reconnected. These are all hard wired devices. No
other devices on the network are experiencing an issue, just a particular
group. I have many XP machines that do not report the network
dis/reconnection. My servers report no issues.

A common thread was that all of the affected users plugged into a specific
switch. However, I've move one off to another segment and it still has the
issue. A machine plugged into the segment where that user came from now
reports no issues. I've virus,ad, and spy scanned and found nothing.

The network logs report no issues, the client logs do show a TCPIP
disconnect, reconnect, and a Broadcom Apdapter up message in the event log.

Anyone have any thoughts?

Hi, exact same problem, since 2 days ago (started about 17:00 CET on 30 Nov.
It coincided with a problem at my ISP (wanadoo/phone company). They are
solving that for me, but from my local area connection I get either a message
saying "limited or no connectivity" or it flashes on and off (connected,
disconnected) as you describe. If I try "repair" on the local area
connection, it says it "cannot renew my IP adress" (on the network).
(network adapter = intel pro/1000MT)
The technical people at my ISP/phone company said, scrap SP2, do a system
restore to before you installed it!
Ray

"Steve" wrote:

I have a group of PCs running WinXP Pro. They have all been running fine for
about 6 months, but in the last several days all of them go through phases
during the day where every 1 sec it reports a network disconnected and then
1 sec later a network reconnected. These are all hard wired devices. No
other devices on the network are experiencing an issue, just a particular
group. I have many XP machines that do not report the network
dis/reconnection. My servers report no issues.

A common thread was that all of the affected users plugged into a specific
switch. However, I've move one off to another segment and it still has the
issue. A machine plugged into the segment where that user came from now
reports no issues. I've virus,ad, and spy scanned and found nothing.

The network logs report no issues, the client logs do show a TCPIP
disconnect, reconnect, and a Broadcom Apdapter up message in the event log.

Anyone have any thoughts?

Thanks for the info!

I tracked down/confirmed what I was beginning to suspect last night. In my
case, I had (3) 3COM switches that while reporting a client connection had
several ports on each where it kept dropping the connection. All status LEDS
were reporting normal operation until at one point, a particular switch just
entered a continual power cycle phase (assuming a power supply problem).
Rerouted clients on the suspect switches and all issues disappeared. Pulled
the suspect switches into a test environment - completely seperate from
previous environement - and surprise! all the problems resurfaced.

I support two companies. Company A has (8) 3COM switches and Company B has
(3) 3COM switches. Each company also has some other brands in more limited
use such as Cisco, Netgear, and Linksys. However, all switches are in the
same rack with the same power source, etc. Company A has had (6) switch
failures and Company B has had (2) switch failures over about 4 years and
all of them were the 3COM Superstack 3300s. No other brand switch has failed
in that period. Both companies have power protection throughout, no unusual
happenings, storms, etc that would warrant such a rate of failure. Probably
not a good message board for this anymore, but wow, from this experience we
have no choice but to look to other brands for future
expansions/replacements. 3COM carried the "lifetime warranty" (be awa
lifetime of product support though!), so to daye they've replaced switches
fairly well, but it likely time for us to move on to other brands rather
than dealing with such a fail rate.

"Ray" wrote in message
...
Hi, exact same problem, since 2 days ago (started about 17:00 CET on 30
Nov.
It coincided with a problem at my ISP (wanadoo/phone company). They are
solving that for me, but from my local area connection I get either a
message
saying "limited or no connectivity" or it flashes on and off (connected,
disconnected) as you describe. If I try "repair" on the local area
connection, it says it "cannot renew my IP adress" (on the network).
(network adapter = intel pro/1000MT)
The technical people at my ISP/phone company said, scrap SP2, do a system
restore to before you installed it!
Ray

"Steve" wrote:

I have a group of PCs running WinXP Pro. They have all been running fine
for
about 6 months, but in the last several days all of them go through
phases
during the day where every 1 sec it reports a network disconnected and
then
1 sec later a network reconnected. These are all hard wired devices. No
other devices on the network are experiencing an issue, just a
particular
group. I have many XP machines that do not report the network
dis/reconnection. My servers report no issues.

A common thread was that all of the affected users plugged into a
specific
switch. However, I've move one off to another segment and it still has
the
issue. A machine plugged into the segment where that user came from now
reports no issues. I've virus,ad, and spy scanned and found nothing.

The network logs report no issues, the client logs do show a TCPIP
disconnect, reconnect, and a Broadcom Apdapter up message in the event
log.

Anyone have any thoughts?