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DHCP - Reservations & Unauthorised Access

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#1 Guest_WelshSteve_*


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Posted 18 November 2011 - 09:41 AM

Hi everyone.

Does anybody know how I can block unauthorised computers from obtaining a DHCP address lease in our Windows Server 2003 environment?

One particular person is plugging themselves into a mini switch and gaining access to the network/internet, which I'm not happy about because I have no way of telling whether they have decent AV and firewall etc on the machine.

As this PC no doubt has it's adapter settings set to "auto", one thing I have tried is to create a reservation for the computer's MAC address in DHCP, and set the IP to be outside the address pool. Should this stop it working? ...and how do I give this reservation an incorrect default gateway to stop them gaining internet access?

I have configured ROUTER, DNS SERVERS and DNS DOMAIN NAME to be complete rubbish, not even using the same IP class etc

Will this work?

Many thanks in advance

Edited by WelshSteve, 18 November 2011 - 09:47 AM.

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#2 keyboardNinja


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Posted 19 November 2011 - 08:23 PM

I found this information regarding filtering DHCP requests by MAC address:

Let me know if this works for you or not, as I've never tried it. It should work though, as the info originates from a Microsoft Technet article.

Edited by keyboardNinja, 19 November 2011 - 08:25 PM.

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