Win2K DHCP not handing out available addresses..

[thatguy]

Hey all -- This has got me stumped. First off, I'm walking into this very poorly structured/maintained network, so I have no idea where it's come from.

So the Win2k DHCP is reporting 100% of its addresses are taken, but looking thru the leases, there are gaps of addresses available - about 50 available IPs. Pinging most of the IPs gives a "destination host unreachable" (some ping back, so I'm assuming that those are statically assigned? but they're not reserved, so why wouldn't DHCP assign them and just cause a conflict??)..

Thoughts? Suggestions? I'm confused.
Thanks!

 

[ShackDaddy]

Three possibilities I can think of:

1. They have a RRAS server there that's reserving chunks of it but they aren't in use.
2. There are exclusion ranges set up to keep some sections of the range from being used.
3. If the server tried to give out an IP at some point but the IP was in use, the DHCP server will mark that IP as "bad" and not give it out anymore (at least for a while, maybe for a long time). That would explain why some of the IPs are pingable. DHCP will not hand out the address if it is pingable--DHCP tries to ping an IP before handing it out.

Dave Shackelford
ThirdTier.net
TrainSignal.com

 

[thatguy]

This problem may have worked itself out, oddly enough..

A maintenance guy accidentally shut off a circuit breaker to the server room, which, eventually (when the UPS died), shut down the Win2k server. When it came back up, there were 84 leases with the IP address listed as the device name.. along with the correct lease (shown with the computername.domain.loc).. the IP-address-named leases were not shown before the reboot..

I deleted the IP-address-named leases and am waiting for the morning logon rush to see if the dhcp server will re-lease those addresses or behave correctly now.

Murphy's law - it only hurts until you go to the doctor.. or until the maintenance guy shuts off the power to the server room.

thanks