Cable Modem/router: Wireless Works, Wired Does Not

System: Windows 7 Home Premium 64 bit SP1
Laptop: ASUS K52F

At my previous location I connected to the Internet via DSL modem. At my new residence, I connect via cable by Cox Communications. Cox supplied a cable modem/router, UBEE model DDW365. This is a DOCSIS 3.0 WiFi modem that has 4 wired Ethernet connections.. The wireless connection to the modem works fine and I get my required download speed. However the wired connection does not work. When I look at network adapter settings, it shows the LAN network cable as "unplugged". I have tried 3 different Ethernet cables without success. When I called Cox they suggest I go to their office and get a new modem since the wired portion of the modem may be bad.

But could the problem be on the computer end? Wired Ethernet did work properly via DSL at my previous residence. Is there something I need to do now that I have cable rather then DSL? Or is the consensus that the modem is bad and I need a new modem?

 

I agree. Or better yet, buy your own and avoid paying rental fee. I have Cox too, BTW and you don't have rent from them and, over time, end up paying a lot more than if you buy your own. I have my own DOCSIS 3.0 modem connected to my own wireless router and they work just a well as that device you rent from Cox. Yes, they cost more up front, but compared to a year or two in rental fees, pay for themselves. Or if you like them all in one box, you can go that way too. Here is Cox's list of "approved" devices. Something to think about.

Yes, it could be your computer. But since this same computer worked before via Ethernet with your DSL modem, unless the computer was dropped or something during the move, it should work fine here. But still, unless you have an Ethernet "card", it is not likely any damage occurred. And motherboards have used integrated Ethernet for many years so hardly anyone uses an actual "card" any more.

Ethernet is Ethernet. It does not matter if your network connects to the Internet via cable or DSL.

One thing to understand, you have a "4 in 1" integrated network device from Cox. This device is really 4 totally discrete network devices that just happen to share a case, main circuit board and power supply. You have in this one box (1) a modem serving as your gateway device to connect you to the Internet. (2) A router to connect your network to the modem. (3) A WAP (wireless access point) to connect your wireless devices to the router. And (4), a 4-port Ethernet switch to connect your Ethernet (wired) devices to the router. Four separate devices, in one box. And again, Ethernet is Ethernet.

Note that there really is no such thing as a "wireless router". That is a "marketing term" only for an integrated device that has both a WAP and a router (and typically a 4-port Ethernet switch too) in one box. Same idea with a wireless modem. I say this to emphasize that Ethernet is Ethernet, regardless if connecting to the Internet via a DSL modem or a cable modem.

So, since your computer's Ethernet worked fine before, it should still now.

Do you see any errors indicated in Device Manager?

Since your wireless side is working, that means the integrated modem, integrated router, and integrated WAP are all working. Note the WAP typically connects to a 5th Ethernet port internally.

Two things to try. (1) You could have a bad Ethernet port on the Cox device so connect your Ethernet cable to a different port on the Cox device. You should see some lights on the back of the Cox device showing that port is active. If you do, that would suggest your computer's NIC is working. Swapping cables was the first thing to try, so you got that covered.

Another thing that might be causing this and that is if your computer was set before to use a "static" (fixed) IP address from your DSL modem and now your network is set for "dynamic" (DHCP) IP assignment. That is not commonly used, I must say, but if your old DSL service required it, or for some reason you manually set it up that way, it could mean the IP your computer is using is not the same as the new Cox device expects, and you will not have access. See these procedures to make sure your computer is set to "Obtain an IP address automatically". And if necessary, follow these procedures to force Windows to get a new IP assignment from your Cox device.