I have one W2K3 server running as a DHCP server. Inside of that same server I have two virtual machines running fifteen L230s each, for a total of 30, in a lab. Every morning the lab assistant turns on each of the terminals, one by one, at a steady pace. Without fail we get at least one station, and sometimes upwards of three, that inform us that there is an IP address conflict. The stations that have problems are random. It seems that never twice in a row does the same station have a problem.

In addition, turning the station off for 10 seconds or so and turning it back on does not resolve the conflict. DHCP doesn't release the lease, I guess, even though it is in conflict. Obviously DHCP is getting confused somewhere... but where? Any ideas where I should start?

Why don't you assign static ip's to the terminals.  It is easy to do and would resolve any conflicts.

Did you ever check to see if you did not have a rogue DHCP server running from a router or other device?

Also By "stations" are you meaning the thin client box or the windows host PC?

The thin clent boxes get thier IP from the Host PC via nct software.  Is your regular network on the same 192.x.x.x scheme.

If it is the box then you have something in the settings wrong, if it is the host PC and the boxes get them on different IP scheme.

I am 99% certain that I do not have another device handing out IP addresses. After installing the L230s is when I started having these conflict and only on the L230s.

Yes, by "stations" I mean the L230s, not the hosts.

Everything is in the 192.168.x.x range with a 255.255.0.0 mask.

I didn't realize that the IP addresses were being collected from the NCT software. This makes more sense. Since I have about 4 instances (because I have 4 hosts) of the NCT software running on the network, it is possible that they are handing out duplicate IP addresses because they aren't talking to each other. What do you think?

I think you may have something.  That is why I  did static Ip's.  I set the static assignmet so each station could be idenified on the network and via the software. The resaon I asked about the rogue dhcp server is because I had one that keep kickin the units off line.  Turned out to be in VmWare Workstation.  If the ranges are all set the same you could get duplications.

Good luck.

I know static ip's are a pain, but I really think working with that many it is the best solution for you.

I use to work in a school district.  I'd recommend setting aside a block of IP addresses on your DHCP that won't get assigned.  That way you'll always have IPs available to static use.

Just my 2 cents.