[PLUG] Re: Ubuntu And Comcast Digital Cable?

[Jeff Moore]

>I recently upgraded to Comcast Digital with Voice.  The new modem, a 
>motorola SBV5220 seems to be a problem for interfacing with Ubuntu.  I 
>finally got my desktop to interface, but when I swap the ethernet cable, 
>recycle the modem and connect my laptop (an HP Pavilion ze4230 with 
>Dapper, which had previously had no difficulty interfacing with the 
>former modem) absolutely refuses to interface through DHCP.

 If you are directly connecting to the modem then you will most likely have issues with comcast. I am not sure what they do but they lock in the mac of the first host that connects and then deny access to other nic cards that connect(if they have different mac addresses). I am sure this is a measure to help them manage one IP per client. Try setting your Ubuntu mac address to match the other box you have connected(I think you can do it via ifconfig. Please correct me if I am wrong.). Another thing that worked for me was to power cycle the modem. Best solution is to get a firewall switch to front all traffic. 

Jeff M