Intermittent Loss of Internet

[imported_Gelfling]

Hello everyone. I registered with the site in hopes that someone, somewhere can help me. I have replaced several pieces of hardware and had a few ?specialist? out to my office to try and fix this issue, and still, after a year, the problem continues.

I will try and give as much info as possible.

I own my own small business. We have about 30 computers in the office. All computers are on a single network; some hardwired, some wireless. Most of the computers are running XP Pro.

When I turn on a computer, I log in through a server. This server is rather old, and its running Sever 2003 Standard Ed. There are no apparent issues with logging in.

Other relevant hardware includes our Comcast Cable Modem, a Dell Powerconnect 2324 (a switch), CiscoPix 501 (Firewall).

Here?s the problem:

We are intermittently loosing our connection to the Internet. When this happens, it can last anywhere from a few seconds to a few minutes. If I loose my connection, I can still access all the other computers in the office without difficulty. For instance, we have a Dell Server that runs our applications, and when the Internet is down, I can still run those programs. What is really weird, is that sometimes (rarely) ALL the computers in the office loose their Internet connection, but more commonly, its just some of the computers that loose the connection. I can be on a laptop and be surfing away, while someone next to me, with a different laptop (same models) can?t get on.

Comcast has checked our box and said that the box has not ?lost its connection? for days on end. They even tried to ?turn up the volume? as the tech put it, to try and overcome and background noise.

I do the majority of the tech support for the office, although all my knowledge is through my own personal experience. I have no formal training other than working with computers for 20 years. I know a fair amount about hardware and can even fix most software issues, as long as its something I have seen at least once in the past.

Any thoughts?

 

[spidey07]

I can't remember off the top of my head but I think there is a connection limit to the pix501 depending on licensing. That or you've got some kind of virus/worm that is overloading it.

when you have the problem ping or traceroute www.google.com to see where the loss is ocurring.

tracert -d www.google.com

-edit-
yep, 501 had user licensing. Could definitely be what you're seeing. You can check with "show version"

pix501

 

[RebateMonger]

Yeah, PIX license limits are at 10/50/unlimited simultaneous users. I'd take a hard look at that first, since that would match your symptoms. If you suspect the PIX, you can always substitue a temporary cheap SOHO router to see if the problem goes away.

As spidey07 notes, quantifying the problem would help. There are utilities you can install on the Server and on client PCs to keep a "chart" of Internet connectivity.

If you can reach the server from all of the PCs, but your Internet connectivity is failing, it sounds like your local network is working fine. That pretty much relegates the issue to your Default Gateway and beyond. Of course, as always, take a look at DNS, too, to ensure it's functioning as expected.

 

[imported_Gelfling]

I say to the both of you, "THANK YOU!" It was the license issue!!! I have had countless people out here and spent hours on my own tring to figure this out.

I went around the office and started an audio stream to each pc. I monitored the Users via the Cisco interface. When I tried to access the net on an 11th machine, it would not connect. (Well, once it let me get to 11 licenses as I was watching the Cisco Monitor, but when I tried to do that again it would not let me.) SO.....it seems that this is likely the issue. Whether I'm gettting cut off at 10 (or sometimes 11?), is irrelevant. I really need about 15 licenses, so I will need to upgrade by buying a 10->50 user license upgrade. They run about $250, but its money well spend to prevent this ongoing issue.

 

[spidey07]

Good deal. You shouldn't ever have whoever looked at it out again as this is something any "professional" would pick up on real quick.