Mediacom internet issue

[jstory]

Weird issue while trying to set up internet at a clients house. Using mediacom internet. it recently quit working on him, so I went to check it out. The client has replaced the modem, so working with a brand new modem, swapped out the cables, check everything else. What's happening is every time I restart the computer, it comes back up with no IP address. Just 0.0.0.0 . The IP is automatically releasing for some reason. On ever computer, and even the router did it after I tried plugging it in. I try to renew the IP, and it cannot find the DHCP server. So every time, I have to unplug power on the modem, plug back in, then it lets me renew the IP. Once I do that, the internet works, both directly from the modem, and through the wireless router. But I have to go through that same process every time I reboot the computer. Unplug the modem, renew the IP address. It's very inconvenient and I can't think of anything that would cause this issue. I'm thinking it has to do with something on Mediacoms end, but Idk what it would be, and when we contact them, they just say it's our end. I need to know where to go from here. It can't be the computer, because the same thing happens on every device I connect to the modem. Any ideas?

 

[RealBeast]

Sure could be Mediacom, but I would start by looking at the router. If you look at the configuration page what does it tell you about the address lease (assuming it is a dynamically assigned address)? If you release and renew it in the router does it pick up an address from Mediacom? Is the DHCP server turned on in the router, with an adequate range of internal addresses? The network computers should all be looking to the gateway (router) for address assignments.