Network brainteaser - a specific PC, when connected, always crashes the network

Hey,

Got a real head scratcher.

I have four computers hooked up to a Linksys router with a 4 port switch.
Two of the computers (Compaq) are running Win2k Server, the other two are
running XP Pro. But the network kept on crashing, to be more specific, the
router would not route traffic to the internet within a couple of minutes of
either Compaq (2k Server) being connected.

I went ahead and formatted one of the Compaq's (I don't know why 2KServer
was on in the first place) and installed XP Pro, thinking the problem may
have to do with the operating system. But the same thing happend, within a
couple of minutes of it being connected, the network would go down.

The machine has 2 NIC's, one on the mobo and one PCI. It happens with every
NIC, but when I took the PCI nic (a Realtek, mobo one is Intel) and put it
into the XP machine, it worked flawlessly.

Does anyone have any ideas? Could it just be that both motherboards are
doing some strange things? I've checked and tested all the cables too.

Thanks,
Adam

Adam Steiner

"Adam Steiner" <> wrote in
news: s.com:

> Does anyone have any ideas? Could it just be that both motherboards are
> doing some strange things? I've checked and tested all the cables too.

Try disabling/removing all the NICs from one of those machines, and
swapping in a known working NIC from another machine. Then check if it
still happens. It's possible the NICs in the machines you have are doing
something funky.

--
AIM: FrznFoodClerk
email: de_on-lag@co_cast.net (_ = m)
website: under construction
Need a technician in the south Jersey area?
email/IM for rates/services

"DeMoN LaG" <n@a> wrote in message
news:Xns94796F3D40C4Wobbly@216.168.3.30...
> "Adam Steiner" <> wrote in
> news: s.com:
>
> > Does anyone have any ideas? Could it just be that both motherboards are
> > doing some strange things? I've checked and tested all the cables too.
>
> Try disabling/removing all the NICs from one of those machines, and
> swapping in a known working NIC from another machine. Then check if it
> still happens. It's possible the NICs in the machines you have are doing
> something funky.
>

Tried it. The problem is I can't swap out the NIC on the mobo, but I did
disable it. The whole thing is strange, no?

--Adam

"Adam Steiner" <> wrote in
news: s.com:

> Tried it. The problem is I can't swap out the NIC on the mobo, but I did
> disable it. The whole thing is strange, no?

Have you tried hooking just the problem machines up to the router, perhaps
using different ports on the router (perhaps one is faulty)?

--
AIM: FrznFoodClerk
email: de_on-lag@co_cast.net (_ = m)
website: under construction
Need a technician in the south Jersey area?
email/IM for rates/services

On Fri, 23 Jan 2004 04:00:42 GMT, "Adam Steiner"
<> wrote:

>Hey,
>
>Got a real head scratcher.
>
>I have four computers hooked up to a Linksys router with a 4 port switch.
>Two of the computers (Compaq) are running Win2k Server, the other two are
>running XP Pro. But the network kept on crashing, to be more specific, the
>router would not route traffic to the internet within a couple of minutes of
>either Compaq (2k Server) being connected.
>
>I went ahead and formatted one of the Compaq's (I don't know why 2KServer
>was on in the first place) and installed XP Pro, thinking the problem may
>have to do with the operating system. But the same thing happend, within a
>couple of minutes of it being connected, the network would go down.
>
>The machine has 2 NIC's, one on the mobo and one PCI. It happens with every
>NIC, but when I took the PCI nic (a Realtek, mobo one is Intel) and put it
>into the XP machine, it worked flawlessly.
>
>Does anyone have any ideas? Could it just be that both motherboards are
>doing some strange things? I've checked and tested all the cables too.
>
>Thanks,
>Adam

Which machine are you talking about?...that's givin' you the problem.
How about givin' them some kind of designation for us...letters,
maybe.

Is the network down?...or just the Internet?

Did you try pinging the router from each machine?...pinging each of
the machines?

How many machines have 2 NIC's? Did you try releasing and renewing
the addresses?

Let us know.


Have a nice week...

Trent

If the cheese isn't yours...its Nacho cheese, man!

Yep. One of the computers was hooked up to a different network and was
running fine for a couple of months. The only difference between the two
networks was my network is running NAT and the other wasn't.

--Adam

"DeMoN LaG" <n@a> wrote in message
news:Xns947916285596FWobbly@216.168.3.30...
> "Adam Steiner" <> wrote in
> news: s.com:
>
> > Tried it. The problem is I can't swap out the NIC on the mobo, but I
did
> > disable it. The whole thing is strange, no?
>
> Have you tried hooking just the problem machines up to the router, perhaps
> using different ports on the router (perhaps one is faulty)?
>
> --
> AIM: FrznFoodClerk
> email: de_on-lag@co_cast.net (_ = m)
> website: under construction
> Need a technician in the south Jersey area?
> email/IM for rates/services

"Trent©" <> wrote in message
news:...
> On Fri, 23 Jan 2004 04:00:42 GMT, "Adam Steiner"
> <> wrote:
>
> >Hey,
> >
> >Got a real head scratcher.
> >
> >I have four computers hooked up to a Linksys router with a 4 port switch.
> >Two of the computers (Compaq) are running Win2k Server, the other two are
> >running XP Pro. But the network kept on crashing, to be more specific,
the
> >router would not route traffic to the internet within a couple of minutes
of
> >either Compaq (2k Server) being connected.
> >
> >I went ahead and formatted one of the Compaq's (I don't know why 2KServer
> >was on in the first place) and installed XP Pro, thinking the problem may
> >have to do with the operating system. But the same thing happend,
within a
> >couple of minutes of it being connected, the network would go down.
> >
> >The machine has 2 NIC's, one on the mobo and one PCI. It happens with
every
> >NIC, but when I took the PCI nic (a Realtek, mobo one is Intel) and put
it
> >into the XP machine, it worked flawlessly.
> >
> >Does anyone have any ideas? Could it just be that both motherboards are
> >doing some strange things? I've checked and tested all the cables too.
> >
> >Thanks,
> >Adam
>
> Which machine are you talking about?...that's givin' you the problem.
> How about givin' them some kind of designation for us...letters,
> maybe.
>
> Is the network down?...or just the Internet?
>
> Did you try pinging the router from each machine?...pinging each of
> the machines?
>
> How many machines have 2 NIC's? Did you try releasing and renewing
> the addresses?
>
> Let us know.

Machine A, B - Compaq Presarios
Machine C - Whitebox (XP Pro)
Maachine D - Dell laptop XP Pro

A, B originally had 2 NIC's each and were each running Server 2K. When
hooked up to a linksys router the internet connection would die. Each
machine can be reached via ping and each machine could log into the router.
Once you clicked 'Save Settings' in the router things would work again for
thirty seconds or so.
Formatted A, put on XP Pro. Same thing. Took one of the NIC cards out of
B and put it in C, NIC worked perfectly, no problems whatsoever.

So it doesn't appear to be the NIC's, they work (at least the removable
ones). Doesn't seem to be the OS because it's the same problem across XP
and 2K. Happend with a DLink and 2 Linksys routers. Same problem whether
DHCP was enabled on the routers or not. Only thing I can come up with is
that something is screwy with the computers...but what I don't know.

--Adam

> Machine A, B - Compaq Presarios
> Machine C - Whitebox (XP Pro)
> Maachine D - Dell laptop XP Pro
>
> A, B originally had 2 NIC's each and were each running Server 2K. When
> hooked up to a linksys router the internet connection would die. Each
> machine can be reached via ping and each machine could log into the
router.
> Once you clicked 'Save Settings' in the router things would work again for
> thirty seconds or so.
> Formatted A, put on XP Pro. Same thing. Took one of the NIC cards out
of
> B and put it in C, NIC worked perfectly, no problems whatsoever.
>
> So it doesn't appear to be the NIC's, they work (at least the removable
> ones). Doesn't seem to be the OS because it's the same problem across XP
> and 2K. Happend with a DLink and 2 Linksys routers. Same problem
whether
> DHCP was enabled on the routers or not. Only thing I can come up with is
> that something is screwy with the computers...but what I don't know.
>
> --Adam
>
>

If you only have the XP box on, will the Network go down. And is it the
Network or the internet? What is your address before and after it goes
down. Once it goes down, is your modem still communicating with your ISP?

Let us know,

Dave H.

On Fri, 23 Jan 2004 16:45:54 GMT, "Adam Steiner"
<> wrote:

>Machine A, B - Compaq Presarios
>Machine C - Whitebox (XP Pro)
>Maachine D - Dell laptop XP Pro
>
>A, B originally had 2 NIC's each and were each running Server 2K.

If you don't need both the on-board and the PCI NIC's, uninstall and
take out the PCI NIC's. Make sure you disable DHCP in the operating
systems...but not on the router.

>When
>hooked up to a linksys router the internet connection would die.

Die? Does that mean you'd be able to access the Internet for a period
of time after you hooked up the Linksys?...and after a period of time
you wouldn't? Or does that mean that when you hooked up the Linksys,
you IMMEDIATELY wouldn't be able to access the Internet?

>Each
>machine can be reached via ping and each machine could log into the router.

So you went and got the address for each machine?...and pinged that
address? Did you ping by name, too?

>Once you clicked 'Save Settings' in the router things would work again for
>thirty seconds or so.

Things? You need to be more specific. What worked?...what
didn't?...SPECIFICALLY!

>Formatted A, put on XP Pro. Same thing. Took one of the NIC cards out of
>B and put it in C, NIC worked perfectly, no problems whatsoever.

Did you check Device Manager after the install? Did you get a notice
that new hardware had been detected? Maybe the card never even got
installed...hence, no conflict.


>So it doesn't appear to be the NIC's, they work (at least the removable
>ones). Doesn't seem to be the OS because it's the same problem across XP
>and 2K. Happend with a DLink and 2 Linksys routers. Same problem whether
>DHCP was enabled on the routers or not. Only thing I can come up with is
>that something is screwy with the computers...but what I don't know.

I don't think its a computer problem. But it could be a router
problem/conflict of some kind.

Also, try resetting the router when this happens. But make sure you
read the manual on how to do the reset.

Run ipconfig before and after the problem...to see what has changed.

Good luck...let us know.


Have a nice week...

Trent

If the cheese isn't yours...its Nacho cheese, man!

"Trent©" <> wrote in message
news:...
> On Fri, 23 Jan 2004 16:45:54 GMT, "Adam Steiner"
> <> wrote:
>
> >Machine A, B - Compaq Presarios
> >Machine C - Whitebox (XP Pro)
> >Maachine D - Dell laptop XP Pro
> >
> >A, B originally had 2 NIC's each and were each running Server 2K.
>
> If you don't need both the on-board and the PCI NIC's, uninstall and
> take out the PCI NIC's. Make sure you disable DHCP in the operating
> systems...but not on the router.
>
> >When
> >hooked up to a linksys router the internet connection would die.
>
> Die? Does that mean you'd be able to access the Internet for a period
> of time after you hooked up the Linksys?...and after a period of time
> you wouldn't? Or does that mean that when you hooked up the Linksys,
> you IMMEDIATELY wouldn't be able to access the Internet?

Approximately thirty seconds to a minute after hooking up the Compaq's to
the Linksys router, the connection to the Internet would die. It seems to
happen as soon as the Compaq makes a request to the Internet. The first
page loads, but everything after that, on the entire network, doesn't work.

>
> >Each
> >machine can be reached via ping and each machine could log into the
router.
>
> So you went and got the address for each machine?...and pinged that
> address? Did you ping by name, too?

Ping by name, by address. Even after the connection to the internet died,
the internal LAN would still work. The Compaq's (and other computers)
despite not being able to access the internet, would be able to access the
router.

>
> >Once you clicked 'Save Settings' in the router things would work again
for
> >thirty seconds or so.
>
> Things? You need to be more specific. What worked?...what
> didn't?...SPECIFICALLY!
>
> >Formatted A, put on XP Pro. Same thing. Took one of the NIC cards out
of
> >B and put it in C, NIC worked perfectly, no problems whatsoever.
>
> Did you check Device Manager after the install? Did you get a notice
> that new hardware had been detected? Maybe the card never even got
> installed...hence, no conflict.
>

New card was installed and working.

> I don't think its a computer problem. But it could be a router
> problem/conflict of some kind.
>
> Also, try resetting the router when this happens. But make sure you
> read the manual on how to do the reset.
>
> Run ipconfig before and after the problem...to see what has changed.
>

I'd tend to agree with you, but I can't figure out what the conflict would
be with the router. I didn't see anything on the Linksys or DLink (tried
one of their routers too) website. I did a hard reset on the router a few
times, but it didn't help. All of the computers have valid IP's
(192.168.1.*) both before and after the internet connection dies.

To recap, the internet won't work, but the LAN is working fine. The
computers can ping each other, and each computer can access the router, but
nothing can access the internet.

--Adam