Recently a lot of issues have turned up with my ISP provider, Reliance Communications in this case. I happen to use multiple laptops and a router. They lock a system based on MAC address or a long duration dhcp lease file. There are various ways to get rid of this situation. A few which I could figure out and seem to work are

– Do neatly logout of their web application, before switching machines. As they keep the records, which would not let you login using a different machine till a session timeout which ranges from 0.5 to 6 hours.

– Spoof Your MAC Address, if you are using multiple laptops/desktops

use ifconfig utility:

MAC address can be changed very easily using ifconfig. Run the following command as root user.

#ifconfig eth0 down hw ether address

eth0 is the name of the interface/NIC which address is to be changed.

down means the NIC is to be shutdown before changing address.

hw ether means hardware address class is ether(which indicates ethernet).

address is the address which will used as the new mac.

After the successful execution of the command. start the NIC again using the command:

# /sbin/ifconfig eth0 up

– Release your IP after successful log out

# dhclient -r -pf  < path to the current dhclient pid file >

The path of current dhclient pid file can be found using

# ps -eaf  | grep dhclient

Path is usually /var/run/dhclient-eth0.pid or /var/run/dhclient-wlan0.pid