DHCP handing out os scope address.......

[Frankenherder]

OK I thought I have seen it all but this one is good!

I have one Wyse thin client that all of a sudden was being handed out the IP address of the internal side of my firewall!

Needless to say there was an IP conflict on the network and lots of problems.

I have a Windows 2000 server running the DHCP service and the IP address is not even in the range. Our internal subnet is 200.8.X.X so it is not like an employee could plug in a router or something from home since they usually default to 192.168.X.X

Has anyone every heard of an out of scope IP being handed out? The default GW is my firewall, it is like it is taking the Default GW as it's IP.

I have since hardcoded a static IP and it works fine but I need to find out how and why this happened before tomorrow all of my thin clients get this problem.
Thanks
Matt

 

[burtsbees]

Is it possible that there is another device doing the DHCP??

Burt

 

[Frankenherder]

I suppose anything is possible but it is just me and my boss in the IT department. It would have had to have been malicious though.

I can plug my notebook into the same port and I get a valid IP, I plug the thin client in I get the same bad port. Not sure if there is a MAC address issue or something cached somewhere but I am leaning towards a hardware problem with the Thin client.
Matt

 

[SimonDavies]

Out of interest what's the IP address it's getting? Could it be hardwired in?

SimonD.

The real world is not about exam scores, it's about ability.

 

[Frankenherder]

it is getting the IP of my default gateway. So it's default gateway and the IP address are the exact same.
The default gateway's address is not in my scope at all. I have verified that the thin client is on DHCP.

This is really weird and goes against all rules of DHCP

Matt

 

[SimonDavies]

Do you have another thin client that you can use? Do you see anything in the event viewer on the dhcp server?

SimonD.

The real world is not about exam scores, it's about ability.

 

[Frankenherder]

Event viewer is clear for DHCP.

I stopped and started the service and it still happens.

There is one right next to it. I will swap network cables and see what happens. I wonder if the port on the switch is messing up or something...

 

[SimonDavies]

I was wondering about the device, you have already mentioned that you plugged your notebook in and can successfully get a valid IP (you did do an ipconfig /release and /renew didn't you?).

SimonD.

The real world is not about exam scores, it's about ability.

 

[Frankenherder]

there is no option for a release or renew. It is using a proprietary operating system. I have about 45 of these devices and this is the only one.

i am going to call the manufacturer. I did do a factory reset but that did not help either.....
Matt

 

[SimonDavies]

The /release /renew was on your laptop rather than the thin client.

SimonD.

The real world is not about exam scores, it's about ability.

 

[Frankenherder]

Sorry, mis-understood. I did release/renew on my laptop.

 

[mattKnight]

IIRC, Wyse thin client also respond to BOOTP. Is it possible that you have something giving BOOTP addresses.

This would explain why your laptop works ok...

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[Freestone]

Have you tried stopping the DHCP service, then booting the suspect thin client device and seeing if it receives an address? If it does, it isn't your DHCP server, but the device itself, a rogue DHCP server, or a BOOTP server as suggested by mattKnight.

 

[Bas1234]

Try another port on the switch, it could be that the switch has VLAN's and that you are in the DMZ of your Gateway.

___________________________________________
It works! Now if only I could remember what I did...
___________________________________________