Services

I have a user that is making dhcp requests several times a minute and I'd like to know if there is anyway to deny them access to the system and requesting from the dhcp service?

You need this:
http://ranum.com/security/computer_security/papers/a1-firewall/index.html

In other words, cut the cord on the offender.   

You can't really deny them access, you could setup a reservation for the offending machine and give them an address that's blocked from getting to the Internet.

Well they have no host name so that makes me wonder also.  Most of the system is wireless so I was planing to goto each AP and see if I could find them on one and then deny them there so that way they could not get to the DHCP server.  Just have not had the motivation yet as they have about 30 APs.

Thanks for the info on that other software though, I might be able to use that for some other things.