Wake On LAN and MAC Address

Posted on 2007-08-07
Last Modified: 2010-08-05
Dear Community -

A great need arises this evening.  I am over 6000 miles away from a small network for which I offer ad-hoc support.  

One of the PCs has a dodgy Power Button on the Front Bezel, a DELL OptiPlex GX110.

The MD of the company has shut it down and cannot get it back up.

The PC  MB and NIC support Wake on LAN, just need to get MAC address.

However, cannot find MAC since PC is down.

Have checked the arp cache of the Router and no can do.
Have checked DNS, Active Directory, no can do.
Have checked WINS, no can do.
DHCP is not working on the network since senstive in nature and MD thought it posed a security risk.

I need that MAC address in order to do a Wake on LAN.

Anybody can help please? A way to find MAC on Power-Off PC which is not coming back up.  Or even a way to do a broadcast to anything on network powered-off, power on-WoL.

Please help.
Question by:ActiveInfoSys
    LVL 87

    Accepted Solution

    Knowing the MAC address wouldn't help if the wake on LAN function hasn't already been enabled inside the BIOS, and by default such options are always disabled. So you'd still need someone there to first start the PC and enter the BIOS then enable "Wake on LAN". For that he'd probably have to open the case and manually short circuit the connector on the mainboard that goes to the power button. Since he needs to open the case he should also read the MAC address either from the NIC, as that is usually printed on it as a serial number, or if it is integrated on the mainboard, it would be printed somewhere on that (or possibly also on one of the stickers on the case, probably close to where the service tag sticker is).
    LVL 29

    Assisted Solution

    by:Alan Huseyin Kayahan
             Hi ActiveInfoSys
                  rindi is right. Even you power it on somehow, the stuck power button may shut it off back or cause it to never power on.
                In such cases, I used to remove the connector of power switch on mainboard (PW SW or PW) and plug the connector of Reset button to power, and user can power up/down the PC by using the reset button and go on working untill the new case arrives.

    LVL 65

    Assisted Solution

    Hi, you could also run a login script to aquire the MAC address, and output it to some central share, so that, over time, you will gradually get a list of MAC Addresses.  Also, if you have Dell machines, there's an EnableWOL.exe utility that can enable this feature (when run as an Administrator) from within Windows.

    Other than recording the MAC's at logon, DHCP is the only way I know of to obtain them.


    LVL 28

    Assisted Solution

    by:Bill Bach
    Of course, there's only 281,474,976,710,656 possible MAC addresses, so you could try all of them.  If you know the NIC manufacturer, you may know the first three bytes, so you'd be down to only 16,777,216 choices.  

    Of course, it might take less time to drive the 6000 miles back to the box...

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