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I am working on Ubuntu OS.

Initially my pc configuration was Intel core 2 duo 3.0GH with 320 GB HDD. After some times, my friend changed the motherboard with lower version of configuration without changing the HDD.

Still the Ubuntu OS is working fine and all data is safe. I want to know that from where I would know the previous MAC address(the machines physical address)? Does the system keep any log file in Hard disk ? If yes, then how to know?

please help

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If the machine is using DHCP to obtain an IP address, you should be able to find it in the syslog if it wasn't too long ago. Open a terminal and type

sudo zgrep "dhclient: Listening on" /var/log/syslog*

You will see a listing of all the MAC addresses and interfaces that dhclient has listened on. The oldest ones have the highest number in the name of the file (e.g. syslog.8.gz), but the lines should be timestamped anyways.

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Yes the machine is using dhclient.. For how many old days will it show ? – MAHFOOZ Mar 14 '12 at 18:21
Actually my machine is obtaining IP from DHCP (WAN), Will it work? – MAHFOOZ Mar 14 '12 at 18:26
It looks like the default for Ubuntu is to keep 4 weeks of backlogs. – pestilence Mar 14 '12 at 18:32
Still I am unable to fetch data .. kindly help – MAHFOOZ Mar 15 '12 at 3:58
You need to be more specific about what you are having trouble with. – pestilence Mar 15 '12 at 14:00

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