Sudden Internet Inactivity

[star_topology]

I've been dealing with one the most bothersome issues lately.

We have a user who is using a refurbished Dell Optiplex DX1. We have a few of these machines issued for service, and have been quite reliable.

The NIC is built on to the motherboard.

During any given period of time, she will be using the internet, and after a few minutes of problem-free browsing, IE will stop working, citing the common 'page cannot be found' error that is normally seen when a cable is unplugged, etc. However, I can continue to ping the vital parts of our network (gateway, T1, etc).

I have tried altering IP information, and I just got back from installing a new NIC and disabling the onboard one. Same thing as before, a few minutes of browsing, then inactivity. A restart cures this, but I don't want such a 'patchwork' fix. Aside from replacing the computer, does anyone have any ideas of what I'm dealing with?

 

[The_Urge]

Sounds like a spyware issue. Try adaware and spybot and see if they cleans things up a bit.

 

[harrytewkesbury]

Urge might have a point. Do these things and once scanned etc, see if the connection icon in the system tray is active even if IE is not running. If so, then something on the system is hogging the connection. If not, then there may be other issues to address.

 

[Inaris]

what kind of network do you have? switch/router hardware, server OS and how is DHCP/DNS done?

have you tried doing an ipconfig /flushdns to see if that corrects the problem?

what are your nic and port speeds set at?
do you use Wins?

what is the IE cache size set at? Also, what are IE's settings defined as?
have you tried another browser?

 

[star_topology]

Here's another oddity that I discovered today while I was working on the machine: I found that I can disable and re-enable the Network Connection and I will have connectivity for a few minutes until it goes out again. This computer was recently reformatted (via Ghost), so it's in essence a new computer, but there is a remote(?) possibility that some network file was not copied correctly. We may just issue her another computer to troubleshoot the issue further. But as far as the questions go...

Harrytewkesbury

That is generally one of our department's first troubleshooting methods. Spybot and Ad-Aware are fixtures in our network's Share folder, but alas, nothing serious was found.

Inaris

what kind of network do you have? switch/router hardware, server OS and how is DHCP/DNS done?
We have an ethernet star topology (sound familiar? ), our UNITY box distributes DHCP/DNS. We have a mixed Win2000/2003 Server environment, but this part of the network is 2003. Our switches and routers are all Cisco.

have you tried doing an ipconfig /flushdns to see if that corrects the problem?
Yes. No fix there.

what are your nic and port speeds set at?
I've never had to change these before. So I assume they are at their default speeds. Why/How might we need to change them?

do you use Wins?
Yes. Some computers on the other side of the router use WINS to authenticate to our server. However, I feel this is unrelated.

what is the IE cache size set at? Also, what are IE's settings defined as?
Cache is a default 200-300mb. I'm not sure what other settings you refer to, other than a proxy setting, which is disabled.

have you tried another browser?
Yes. Mozilla Firefox also experiences the same problems.

Thanks again, guys. It helps just to have someone bounce these ideas off of, rather than the ol' boss man.

 

[Inaris]

are there any definitions in the hosts file? %systemroot%system32\drivers\etc\hosts

do you use a proxy or firewall? have you seen anything on there that is limiting the traffic? do you use ACL's for network access? Do you have a web filter? what type?

is this what you mean by"Unity box"?