dhcp server from where my interface got the lease on Linux.

There are a number of different DHCP clients that run on Linux. Use the command "ps ax" to try to determine what processes are running that might have something to do with your ethernet interface.DHCPCD is a popular one. Look to /etc/dhcpc for any files that might be there.PUMP is also a frequent program in use by some versions of RedHat Linux. Run "pump -i eth0 --status" assuming your ethernet interface is eth0DHCLIENT -- run "locate dhclient.leases" and look into that file if you see that process running.