The dhcpd installed on your computer has nothing to do with cable modem. Your cable modem should have a dhcp server inbuilt (as with most DSL routers these days).
There should be a way to access admin console of your modem, if it has any, through web browser. Contact modem provider for this. Or try configuring your ethernet card and provide some static ip ex. 192.168.1.10 -- no internet with chello austria cablemodems https://launchpad.net/bugs/83591 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
