DHCP - Strange Behaviour

[brandondaly]

I have DHCP running on Windows 2K server, and for the most part its working fine and behaving itself. However it keeps assigning a reserved IP address. This is a problem as there is already a device using that address on a static (we've not been able to trace the device yet), which is why we reserved the address. Any ideas why the server keeps handing the address out, and what can be done about it.



Regds,
Bran.

There are only 10 kinds of people in this world; Those who know binary and those who don't.

 

[jfwebber]

You state that the address that it is handing out is reserved. Is it reserved using a reservation within DHCP? or do you have it configured statically? If you have it configured statically, does it fall in the rage of your DHCP scope?

Jim

Jim Webber
Network Administrator MCSE CNA

 

[GrnEyedLdy]

When using DHCP to reserve an address within a DHCP scope you must have the MAC address of the device for which you are making the reservation.

You stated above, "(we've not been able to trace the device yet), which is why we reserved the address."

If this is the case, how have you reserved the IP address in question?


Patty

 

[brandondaly]

The address falls within range of the DHCP scope, but I have reserved it within DHCP. Because I do not know the device that already has the address I've been unable to enter its MAC address, instead I entered a MAC address of 0F0F0F-0F0F0F, as none of the devices are expect to have this address. I made the assumption that DHCP would then only assign the IP address to a device with the corresponding MAC address (And I have check that this is not the case).

We have other IP addresses reserved in the same manner and these are not being assigned. We have tried removing and recreating the reservation.

Regds,
Bran.

There are only 10 kinds of people in this world; Those who know binary and those who don't.

 

[GrnEyedLdy]

Hmmmm, interesting...

Is it possible that the client leased the address before the reservation was entered?

Do you have more than one DHCP server handing out IP addresses?

What about simply adding the IP address in question as an exclusion within your scope?

Just a thought,

Patty