New Voip Cable Modem = No access for d-link Router

[DragonD]

I've been with comcast for many years now. I have the triple play thingy with them; internet, cable, digital phone.

I've had my cable modem for about 6 years now, so I decided yesterday to take it into my local comcast office and exchange it for a new one..

And o my, did my troubles start.

The new cable modem (Scientific Atlanta 2203C3) gets signal just fine. If I run my network cable from it straight to the computer, I have no problems getting on the net.

But...i don't want to do that. I have a d-link DGL-4300 (it's both wired and wireless). Both my sons and my gf use the wireless connections for their computer, as well as my ps3.

When I run the network cable from the new cable modem, TO the d-link router and run another network cable from the router to my computer...i can't get on the net.

I CAN access the router, and login it so i know nothing is wrong with it.

For whatever reason, the router can't access the new cable modem. I've done mutiple resets/power downs on each unit, in various order. I've cleared out all setting on the router (factor settings). I've turned off windows firewalls, etc

I'm at a loss. Any suggestions?

 

[ronpaul]

Is the router getting a WAN IP address? If so, is it getting DNS information? Try pinging or browsing to 74.125.45.147, it's Google's IP. If that works, the router isn't receiving DNS information. You can set your clients to use second DNS server 8.8.8.8 which is Google's DNS server.

If you can't get their with the IP, it sounds like your router isn't receiving an IP from the modem. It is possible when you plugged your computer into the modem you monopolized the DHCP lease, in other words Comcast will only give your public IP address to your computer and not the router. If so, you may need to plug into the modem again, run a Command Prompt, and enter in: ipconfig /release

This will release the IP, hopefully telling Comcast's DHCP server that your one and only IP is available again, and then allow your router to take it. But check your router's status pages. If it already has an IP, check the DNS stuff. If it has both an IP and good DNS servers, call Comcast.

 

[DragonD]

I'll try that when I get home today..

I'm thinking it DOES have something to do with the DHCP. Yesterday I unplugged everything, and left it powered down for well over an hour.

I powered up the cable modem first, and let it get it's signal established, then powered up the router...then the computer. I figured that would have sorted the IP grabbing out..but it did not work (IF that is indeed what is going on..)

 

[ronpaul]

Sounds like it's DHCP/DNS anyway. Does your router have the ability to Clone a mac address? If so, clone the PC's you were using. ISP DHCP leases take days and days to expire, I'm not surprised an hour didn't work if it's an address issue.

 

[DragonD]

..that's what it was.

I unplugged the modem and the router, and then released the IP on the computer and shut it down as well.

I then restored power to the modem and let it get it's signal, and did the same with the router. When I turned the computer on, the router had grabbed a new IP and everything was good to go.

thanks for the help...