Drastic Internet Slow-Down

themillerj · Post by **themillerj** » Mon Dec 10, 2007 2:27 pm

I just thought I'd see if you guys had any ideas on this one. We've been having problems with our internet lately and until today I've been blaming our ISP. Our cable lock had been going in and out so I'd been playing phone tag with support until they finally said they would send someone out. Still waiting on him, but that's not the point of this post....

Here is the setup of our network.
Our internet is routed through a Linksys RV082 router. The RV082 is connected to a 24 port switch through which all our traffic travels.
We have three buildings which connect to this switch through fiber runs.
Each building in turn has a 24 port switch which connects to all computers and printers within that building (none of which actually have more than 12 computers).
No new equipment or computers have been added recently.

Today, we had no internet even when we had a cable lock (which was still going in and out) and I noticed a lot of activity from one of the buildings. I disconnected the building from the network and the internet came up. Awhile later, I hooked the building back up to the network and we still had internet access. I believe this activitiy was an extremely large email that was being sent (which I deleted). Since then, however, the internet has been unbearably slow. All internal network traffic is running smoothly though...
We had been having speed issues the past few days so I'm not convinced its not our ISP. Support is supposedly sending someone out to check our modem, cable, etc. so I guess we'll have to wait and see what he says. I just thought I'd see if anyone could point to anything that might be going on with our network.

Spazo · Post by **Spazo** » Mon Dec 10, 2007 5:39 pm

some one could be preforming a DoS attack or some inside could be using like a bittorrent/Limewire type service. You could disconnect the buildings that are not causing the slow-down and somehow(not familar with your router)see all the connections being made from the other building. but since there is not a lot of computers there then just run netstat every computer and see whats doing what.

singularity2006 · Post by **singularity2006** » Mon Dec 10, 2007 10:25 pm

Windows Update could be sucking the life out of your network by downloading it's hundreds of MB of data that is available to update. Have you tried disabling Windows Update to see what happens? Go to your start menu > settings > control panel > automatic updates > set: notify only - do not download.

Post by **YeOldeStonecat** » Tue Dec 11, 2007 6:22 am

Size of your network, is active directory running? If you seemed to isolate it to 1x segment of your network (that other building)..check the PCs in that building. Any worm/trojans causing traffic? A PC get hijacked by a bot? And yes those peer to peer file downloading programs can crush a connection..sucking the life out of it.

themillerj · Post by **themillerj** » Tue Dec 11, 2007 3:12 pm

Well, I thought of trojans and such, but I didn't think about peer to peer programs for some reason. After a little looking I found the culprit. Somebody was having a peer to peer extravaganza. They had about fifty different downloads queued. I guess either people don't realize it will slow everyone down. I'm still trying to figure out how they were able to install the program though. Anyway, thanks for the help!

ErikD · Post by **ErikD** » Wed Dec 12, 2007 6:32 am

Why not block the install AND block the traffic with a proxy? Just a little added protection...