Virtualmin taking down local network

I setup an internal testing server. I have never had a problem with it before (Centos 6.5 64bit). I have just rebuilt it and it’s now online. I’m on DSL and also setup When I turn on the server I can get to everything just fine. My internet works just fine. But the problem is after a few minutes my internet (router) starts to crash till everything is down. I have to reset the router and everything comes up again for a few minutes and repeat. If I unplug the cat5 to the server I have no internet problems at all. Plug in back in and it starts to go down again. I was thinking maybe a DHCP problem but I don’t have DHCP installed in Webmin. I have been trying to figure this out for days and I’m out of ideas. Any ideas or help would be GREAT!!!