I am using Ubuntu Linux for daily purpose. I am using NTC (Nepal Telecom ) Adsl for accessing internet. The connection between NTC and my Laptop MSI CR 400 is through ppoe connection. I get the ip address dynamically from my service provider. Sometime my Ubuntu , currently I am using version 12.04 get stuck for receiving ip address. To solve this I always use one command which really worked me to renew new ip address.
Release current addrss
Renew new address