Randomly losing network connection

two things to try.

1. replace the cable How far away is this computer from the switch? Can you just test with a long cat 5/6 cable?

2. Install a PCI Nic and see if that works

What OS is this computer?

if i understand correctly, you have both the server and pc connected to your internet drop. is this through a switch?  do you have multiple IP addresses available to you?  are you behind a router that is NATting for you?

The computer is running Windows 7 prof.  

I should have mentioned that I tried replacing the cable and I rewired the jack in the wall.  When I got it going by unplugging the cable in the server room, I decided it probably wasn't the cabling.

I have a Nic that I installed. Windows 7 said it installed fine, but didn't work.  (The Nic lights wouldn't come on.)  It's old and might not be Windows 7 compatible.  Before I purchase a Nic, I thought I'd see if there was another solution.

I might have a cable long enough to run straight to the hub in the server room. It would drape through the office, though.

Thanks for the quick response.  I appreciate it.

Steve

Do an ipconfig /all and post results

Move the computer closer if you can and I had a similiar problem where it turned out to be the patch cable in the server room. Try a different port as well

I do have multiple IP addresses available.  The server is set for DHCP.  I don't understand the question about the router NATting for me?  Here's our setup.  Maybe that will answer your questions.

We have the Windows 2003 server that the PCs authenticate to.  The PCs connect with a cable to a wall jack. The wall jack has a cable that's hardwired to our phone/internet hub.  (That way I can switch the jack between phone or network connection.)  The network connections have a cable that runs from the phone/internet hub to a Cisco network hub/switch.  A cable runs from the hub/switch to the server.

For internet, we have a router from our cable company that connects to another router for a firewall.  The firewall router goes into the Cisco network hub/switch.

Because of the setup, it's unusual to have both internet and network connection go down on a PC.  Usually if there's a problem, it's just the network connection.

Steve

Do I need to wait until the connection is down to do the ipconfig /all?

No I want to see what you have

I can't move the computer closer.  I will try a different patch cable and port.

Thanks for all the quick help.  It feels like I'm on a help-desk chat.  :)

Here's IPconfig /all.  (Connect 2 is the Nic I tried to install to fix the problem)

Windows IP Configuration

 

   Host Name . . . . . . . . . . . . : Precision-39-15
   Primary Dns Suffix  . . . . . . . : ce_srv.cenational.org
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : ce_srv.cenational.org


Ethernet adapter Local Area Connection 2:  (I left in the Nic I tried to install to fix the problem)

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Realtek RTL8139/810x Family Fast Ethernet NIC
   Physical Address. . . . . . . . . : 00-60-67-73-7F-7C
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

 
Ethernet adapter Local Area Connection:


   Connection-specific DNS Suffix  . : ce_srv.cenational.org

   Description . . . . . . . . . . . : Broadcom NetXtreme 57xx Gigabit Controller

   Physical Address. . . . . . . . . : 00-1D-09-02-08-6E

   DHCP Enabled. . . . . . . . . . . : Yes

   Autoconfiguration Enabled . . . . : Yes

   Link-local IPv6 Address . . . . . : fe80::a0bc:39a8:27d2:d83%11(Preferred)

   IPv4 Address. . . . . . . . . . . : 192.168.1.xx(Preferred)

   Subnet Mask . . . . . . . . . . . : 255.255.255.0

   Lease Obtained. . . . . . . . . . : Friday, January 18, 2013 7:59:25 AM

   Lease Expires . . . . . . . . . . : Saturday, January 26, 2013 7:59:26 AM

   Default Gateway . . . . . . . . . : 192.168.1.1

   DHCP Server . . . . . . . . . . . : 192.168.1.xxx

   DHCPv6 IAID . . . . . . . . . . . : 234888457

   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-B2-BE-B4-00-1D-09-02-08-6E

   DNS Servers . . . . . . . . . . . : 192.168.1.xxx

   NetBIOS over Tcpip. . . . . . . . : Enabled

 

Tunnel adapter isatap.{1DA51DD6-575B-42C6-9249-3620871FF2A8}:

 

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : Microsoft ISATAP Adapter

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

 

Tunnel adapter Teredo Tunneling Pseudo-Interface:

 

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

 

Tunnel adapter isatap.ce_srv.cenational.org:

 

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . : ce_srv.cenational.org

   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

have you tried a static IP address and received the same results?

Ok I would say you need to eliminate the on board nic.

Get yourself a new pci/pcie nic and try.

Yes old network adapters my not work unless they have an updated driver for windows 7.

If you can not get a new nic then check with manufacturer for an updated driver

But your network structure is fine. Is any one else having this problem? If not then Router Firewall switch are ok.
It is possible that on the switch you could have a bad port too.

I would start with the NIC in the computer first.

Disable the on board one then install the PCI

No one else is having the same trouble.

Since it's the simplest solution, I'll try a new cable plugged into a different port in the switch.  If that doesn't work, I'll buy a new NIC.

Thanks for all the quick help.  

Steve

Switching ports and cables didn't work.  I've ordered a new NIC.

You have two enabled nics on that computer. One is unplugged. The other is plugged in.

Some DELL servers come with FOUR nics. They are separated into two pairs. NICs 1 and 2 are a load balanced pair. NICs 3 and 4 are a load balanced pair. (Off hand, I know Dell 710's and 711's come this way).

The computer's routing table may be looking for the load balanced sets to route to when NIC 1 is busy. In this instant, do one of two things:

1) disable NIC 2 and stop the load balancing. Then flush your ARP cache.
2) plug in NIC 2 and hope your network is configured to allow load balancing over a managed swith network.

Also, I got to ask: DHCP on a server? WHY?

I should have removed NIC 2 on the work station before I ran ipconfig /all since NIC 2 was an attempt to troubleshoot the problem.

By DHCP on the server, I just meant that the work station was getting it's IP address from the server (not a static IP).  I must have used the wrong terminology.  Just showing my ignorance of networking.  :)

The new NIC should be here in a day or two and I'll see if that solves the problem.

Steve

The new NIC didn't solve the problem. I reinstalled Windows, and that didn't help.   I tried plugging the computer into a different network port and it still disconnected from the network.

All the troubleshooting led me to believe there's a hardware problem, probably in the motherboard, so we purchased a new computer.  I'll leave this open for a few days in case we still have the problem.

Steve

Steve

Sorry you are having so much trouble with this one.

Good luck with the new computer I am sure that will work.

Even with the new computer, we're still experiencing the problem.  I'm going to try running a cable directly into the hub.

Steve

Ok this is starting to sound like a cable issue now.

How far away is the computer from the server?

Is the cable a home run or do you have patch cables along the way.

You said plug into hub? Do you have a switch or hub on this network?

How many computers total on this lan?

Can you run a direct cable from this computer to the switch/hub?

If not move the computer near the server as a test and see what happens

Thanks for sticking with me on this.

The computer is about 20 feet from the server.

We have a 3com hub.

There are patch cables.  
  -- 1 patch cable runs from the computer to the wall.  
  -- From the wall, a cable is hardwired into the "phone hub."  (The phone hub branches to either our phone system or network so we can run either phone or network through the same cat 5 cable.)
  -- Another patch cable runs from the "phone hub" to a 3COM hub.
  -- The last patch cable connects the 3COM hub to the network

This morning I ran a cable directly from the computer to the 3com hub.

We have about 15 computers on the network.

Steve

The direct cable has worked fine all week.  It looks like I better shop for a managed switch.

Do you have a managed switch you would recommend?  I see they're available for around $100.  

http://www.staples.com/CISCO-ESW-520-24-28-Port-10-100-1000-Gigabit-Ethernet-Managed/product_IM1GC4668

To close to $1,000.

http://www.staples.com/CISCO-SF300-08-8-Port-10-100-Fast-Ethernet-Managed-Switch/product_IM1BC4103

Can you give me an idea of what the advantage would be in paying more?

Thanks,

Steve

your first option will work with your setup just fine, the second option gives you more growth because it is a layer 3.  However the first option is gigabit ethernet and the second is only Fast ethernet.  if the first option works with your setup and will give you enough ports for now and some for future expansion go with that.  if you fill it all up then you might need to go with a larger one (more $$) or go with your second option.

-=Richard

Thanks for helping me narrow down the problem.  I appreciate it very much.