CentOS 6.7 slowing down entire network

Hi all, thanks in advance.

Disclaimer, I am extremely new to Linux in general.

My Centos machine is entirely bogging down my network, and I am unsure of how to proceed with troubleshooting the problem.

When the machine is off/disconnected from the network I have 55+down/up on wired connections and roughly 30d/u over wifi. A few quick ping tests out to google from both the server and my windows PC show 0% packet loss and low ping.

When it's on, I have trouble staying connected at all, and speeds can vary wildly. Pinging out either times out completely, or shows significant delays.

I am also at times unable to ping the router from either machine when the server is up.

I have DHCP disabled on the server and running a static IP.

I have already replaced the switch the server and PC were connected to, but I can't imagine why a bad switch would have caused the wifi issues anyway.

Where do I begin? I found that there were some similar issues with Ubuntu with some quick googling, but I'm not sure how related it could be.

Thanks.

Edit: Forgot to add, this is a fresh install from only about a week ago, minimal install. Working entirely with command line.

UPDATE : I can not see any kind of IP conflict on the router side, but I will be checking via command lines on the server this evening. I have confirmed that for a couple of hours while the server was up and running that the network was affected (including killing communication between my DVRs) and immediately worked again once I shut down the server.