DHCP reservations active/inactive

[Bart Vanhoutte]

I have a LAN with +- 500 pc's. We work with DHCP on a Windows 2003 server.
Every pc gets a dhcp-reservation according his MAC-adress. Once a pc
activates his reservation, it stays active for ever. But pc's come and go.
New pc's are no problem for a new reservation because I know the new pc's.
But when an old pc leaves the network, I can't see that because the
reservation stays active. Is there a way to deactivate a reservation
automatically when its not used for a long time? Or even to delete the
reservation automatically?

Please help because my IP-range is running out of place.

 

[Lanwench [MVP - Exchange]]

I have a LAN with +- 500 pc's. We work with DHCP on a Windows 2003
server. Every pc gets a dhcp-reservation according his MAC-adress.
Once a pc activates his reservation, it stays active for ever. But
pc's come and go. New pc's are no problem for a new reservation
because I know the new pc's. But when an old pc leaves the network, I
can't see that because the reservation stays active. Is there a way
to deactivate a reservation automatically when its not used for a
long time? Or even to delete the reservation automatically?

Please help because my IP-range is running out of place.

If the computer isn't connected & receiving the IP address, it shouldn't
show up as active in your DHCP server, AFAIK.
If you must maintain this method (and for 500 computers I sure as h__
wouldn't want to)
perhaps there's a better way - even involving a company requirement that
anyone removing a computer from the network notify whoever is responsible
for maintaining the server. Not a very technical solution, but it might
suit.
Or ditch the reservation idea - there may be a better way to do what you
want (which is, I presume, to prevent wandering laptop users from plugging
into your network).

Check out the thread entitled "DHCP Security" posted by Andy Siegel on
10/27....particularly Stephen Umbach's reply.