Odd connectivity problem with Cox

rwjones · 06-25-2008, 08:46 AM

A friend has Cox as an ISP. He is able to connect to the Internet perfectly using his Mac Book Pro laptop via the Motorola modem that Cox provided.

When I tried to connect via the same modem using a Dell laptop running Windows XP Pro SP3 (set for DHCP), I could not even get an IP address.

So...I hooked up a Linksys router to the modem, and cloned the MAC address from his Mac Book Pro on the WAN side.

With that configuration, the modem assigns a Cox IP address (72.xxx.xxx.xxx) on the WAN side...it provides three DNS servers...it provides a Gateway address...etc. So far, so good.

On the LAN side of the Linksys box, I get a 192.168.1.xxx address, a Gateway address...etc. But I still cannot connect to the Internet.

Moreover, when we hook up his Mac Book Pro to the Linksys box, he can no longer connect to the Internet...he can only connect to it via a direct connection to the Motorola modem.

Anyone have a clue what's going on here, or what I might be doing wrong?

Thanks.

matt261102 · 06-25-2008, 08:55 AM

Why did you clone the MAC address from his Mac Book Pro?

rwjones · 06-25-2008, 09:37 AM

Quote:

Originally Posted by matt261102

Why did you clone the MAC address from his Mac Book Pro?

I did it on the off chance that when the technician set up the modem, he set it to only work with the one laptop. I had actually experienced this once or twice before, and had been able to solve connectivity problems with that little tweak. In fact, I live in Argentina (and am only visiting the U.S.), and on my home network down there that's exactly what I had to do to get the router to work properly and support the other machines.

**lazareth1** · 06-25-2008, 09:11 PM

First off do away with the router and mac cloning, go back to the original setup where it was a direct connection. Now when you swap the device connected to the modem, you need to power cycle the modem (turn off power for 30 secs and then power on) so that it picks up on the new device's MAC address. This also gets u ur WAN IP address etc and your good to go!

rwjones · 06-26-2008, 08:23 AM

Quote:

Originally Posted by lazareth1

... you need to power cycle the modem (turn off power for 30 secs and then power on) so that it picks up on the new device's MAC address. This also gets u ur WAN IP address etc and your good to go!

Doesn't work.

**lazareth1** · 06-26-2008, 08:01 PM

K. It must be the ISP using some sort of MAC filtering and you did manage to connect the WAN side with MAC cloning on the router I see. Try cloning the MAC address directly on your laptop with out the router. Google to see if you can get any software for this.

06-25-2008, 08:46 AM	#1 (permalink)
rwjones Registered User Join Date: Mar 2005 Posts: 17 OS: WinXP	Odd connectivity problem with Cox A friend has Cox as an ISP. He is able to connect to the Internet perfectly using his Mac Book Pro laptop via the Motorola modem that Cox provided. When I tried to connect via the same modem using a Dell laptop running Windows XP Pro SP3 (set for DHCP), I could not even get an IP address. So...I hooked up a Linksys router to the modem, and cloned the MAC address from his Mac Book Pro on the WAN side. With that configuration, the modem assigns a Cox IP address (72.xxx.xxx.xxx) on the WAN side...it provides three DNS servers...it provides a Gateway address...etc. So far, so good. On the LAN side of the Linksys box, I get a 192.168.1.xxx address, a Gateway address...etc. But I still cannot connect to the Internet. Moreover, when we hook up his Mac Book Pro to the Linksys box, he can no longer connect to the Internet...he can only connect to it via a direct connection to the Motorola modem. Anyone have a clue what's going on here, or what I might be doing wrong? Thanks.

06-25-2008, 08:55 AM	#2 (permalink)
matt261102 Registered User Join Date: Jun 2008 Location: Melbourne, Australia Posts: 155 OS: XP, Vista, Server2003, Fedora	Re: Odd connectivity problem with Cox Why did you clone the MAC address from his Mac Book Pro?

06-25-2008, 09:11 PM	#4 (permalink)
lazareth1 Enthusiast Join Date: Jan 2005 Location: Hong Kong, previously Fife in Bonnie Scotland Posts: 1,294 OS: Vista SP1, Ultimate My System	Re: Odd connectivity problem with Cox First off do away with the router and mac cloning, go back to the original setup where it was a direct connection. Now when you swap the device connected to the modem, you need to power cycle the modem (turn off power for 30 secs and then power on) so that it picks up on the new device's MAC address. This also gets u ur WAN IP address etc and your good to go! __________________ Prime95\|Everest Ultimate Edition\|How to do a repair install of XP\|Bench Testing "Nothing is True, Everything is Permitted"

06-26-2008, 08:01 PM	#6 (permalink)
lazareth1 Enthusiast Join Date: Jan 2005 Location: Hong Kong, previously Fife in Bonnie Scotland Posts: 1,294 OS: Vista SP1, Ultimate My System	Re: Odd connectivity problem with Cox K. It must be the ISP using some sort of MAC filtering and you did manage to connect the WAN side with MAC cloning on the router I see. Try cloning the MAC address directly on your laptop with out the router. Google to see if you can get any software for this. __________________ Prime95\|Everest Ultimate Edition\|How to do a repair install of XP\|Bench Testing "Nothing is True, Everything is Permitted"