Barrhead "optimisation" and MAC address

[seanc]

Hi,
Ever since NTL's planned downtime due to "network optimisation", I've been unable to keep a consistent connection to the internet.

*** Some Background ***

The problem arose when booting my equipment Friday evening.
The symptoms: No internet connection on any computer, 100% packet loss to both domain names and raw IP addresses.

During downtime, the modem's sync and ready lights stay a solid green while the downstream and ethernet LEDs flicker as usual. Originally, the web configuration page of my router displayed a 'correct-looking' external IP address in the range 81.***.**.*** with the relevant gateway but I rebooted the cable modem, router and PCs just to be sure. The router obtains the same IP address. I removed the router from the equation and connect the computer directly to the cable modem.




*** The Problem ***

Sometimes I get served a working IP (like now), often I get one which seems valid but plain wont work no matter how many times I reboot the modem and attempt to refresh my IP address.

My laptop is currently unable to access the internet using its onboard ethernet so I plugged in a cardbus NIC on instruction from the head of NTL's callcentre technical support. Lo-and-behold, it works! No matter how many times I reboot the modem and laptop, the onboard adapter and cardbus NIC obtain differing IP addresses, only one of which actually seems to work.

I cloned the MAC address of my external NIC onto the laptop two minutes ago and I can now access the 'net without some unwieldy card hanging out of my computer but I'd be hard pushed to call this a solution. After all, my laptop was working earlier and I was cloning _it's_ MAC address to obtain a working connection on my _other_ computer.
Does anyone have suggestions on how to refresh a 'working' IP address without changing the MAC addresses round? I'd like to use my broadband with a router and it affords no way to alter the outbound MAC (and has worked flawlessly for the past three years anyway...)

Cheers for reading all this muck, and any help will be appreciated
-Sean

[jonbr]

IP leases are usually set to last several days. So to be sure your current IP address is released, you would have to power off your modem for a few days.
After that, you may still not get a new IP, if the server hasn't reassigned your old IP you could still get it back.

Stick to using your current setup for a week or two and then go back to your old setup. Hopefully the old IP will have been reassigned and you'll get a new one.

Are you sure, however, that this is not just a case of a failed ethernet connection; does the laptop work via the same ethernet connection on another network device (i.e. at work, college, etc..)

[seanc]

Thanks for the reply.
Yesterday I tried my laptop, both with the internal ethernet connection and the PCMCIA adapter, at university and it had no problems connecting to the lan and browsing the web (albeit through a proxy, which I had to disable when I got home).

At home, I directly connected the laptop to cable modem, was given an IP address (In the range 81.109.33.* I think) but still couldn't ping anything. I tried rebooting the modem, releasing and refreshing the IP address but got the following two errors:

"An error occurred while renewing interface Local Area Connection : The DHCP client has obtained an IP address that is already in use on the network. The local interface will be disabled until the DHCP client can obtain a new address."

"An error occurred while renewing interface Local Area Connection : unable to contact your DHCP server. Request has timed out."

So far I've had an enginner visit and called technical support three times. The enginner admitted he didn't know what was wrong, and all but the highest level phone tech didn't have a clue: He suggested there was a problem with DHCP leases not releasing / refreshing which, given the error messages above, I'm inclined to agree with!