Hi all,

We have dhcpd server running on RHEL AS 4. If on a client, user sets a static IP and then sets it to be a dynamic, his machine gets the same IP from the DHCP server rather than what it was given before by the DHCP server.

e.g.

Step 1 :

Machine set to Dynamic, IP Obtained: 192.168.0.100

Step 2 :

Machine assigned a static IP : 192.168.0.200

Step 3:

Machine set back to Dynamic, Obtained IP : 192.168.0.200


In this scenario, in the third step a machine should have got the old one IP i.e. 192.168.0.100 but it didnt get that one. Why is it so? This allows user to have whatever IP he wants. (It is very serious issue when Internet access is given on the IP addresses )

What setting can I do on this, as users having administrative rights can easily change their dynamic IP.

(I am not looking for the solution through Group Policy in Windows Domain Environment.)

Please suggest.......

You could disable dhcp and tell the router to assign IP's according to the MAC address. That's the best I got. But they can still spoof the mac address rather easily.
Bottom line: Users should not have administrative privileges.

Thanx for reply OSKAR,

I'm very disappointed to know that being a DHCP Sever Administrator, I cant do any thing to prevent users, I have to depend on either Network Administrator or Domain Administrator. Hope dhcpd server developers do something to solve this issue.

Well, if you want that everyone has his own IP, it defeats the purpose of DHCP, no? I know next to nothing about networks, but DHCP is just for dynamic... IP... something, right?. In my router I can just switch off dhcp, and assign computers manually.
But, as I said, there are still workarounds. The last resort would be to assign the computer per input (where it is connected to the router) and have every Computer have his Ethernet cable chained to the desk

But the mac-address thing should be good enough. If someone does spoof it, you will find out rather quickly, and have the employee removed.