My DHCP Server is giving out duplicate IP addresses...

[Guest Kelvin]

I'm setting up a new PCs on the network and it is being assigend the same IP

address as another device on the network.

I'm running Windows XP SP2 on the workstation and Windows 2003 server...

Is there some procedure I need to run on my DHCP server?

Is there a database that needs to be rebuilt?

 

If I take this new PC off the net work, I can still ping the IP address.

 

Any help would be appreciated

 

Kelvin

[Guest Jorge Silva]

Re: My DHCP Server is giving out duplicate IP addresses...

 

Hi

Adding to Cali answer, this sometimes happens when you have more than one

DHCP server giving dhcp address (check if no more dhcp servers exist in your

network, or routers with dhcp enabled).

This can also happen when you go to the DHCP console and manually delete the

address that the DHCP server already leased, which will cause the DHCP to

"think" that could give those IPs to other machine requests, to avoid this,

don't manually delete those address, and also configure the DHCP to test the

IP before lease that IP to some machine request, you can configure that in

DHCP server properties.

 

--

I hope that the information above helps you.

Have a Nice day.

 

Jorge Silva

MCSE, MVP Directory Services

 

 

"Kelvin" <someone@domain.com> wrote in message

news:%23IGIz2nPIHA.5016@TK2MSFTNGP06.phx.gbl...

> I'm setting up a new PCs on the network and it is being assigend the same

> IP address as another device on the network.

> I'm running Windows XP SP2 on the workstation and Windows 2003 server...

> Is there some procedure I need to run on my DHCP server?

> Is there a database that needs to be rebuilt?

>

> If I take this new PC off the net work, I can still ping the IP address.

>

> Any help would be appreciated

>

> Kelvin

>

[Guest Thorsten Kampe]

Re: My DHCP Server is giving out duplicate IP addresses...

 

* Kelvin (Fri, 14 Dec 2007 12:17:53 -0600)

> I'm setting up a new PCs on the network and it is being assigend the

> same IP address as another device on the network.

> I'm running Windows XP SP2 on the workstation and Windows 2003 server...

> Is there some procedure I need to run on my DHCP server?

> Is there a database that needs to be rebuilt?

>

> If I take this new PC off the net work, I can still ping the IP

> address.

 

As others have pointed out your explanation for your problem is highly

unlikely. You could use dhcploc (Support Tools) or dhcpdump (runs

under Linux and Cygwin) to find out the rogue DHCP server.

 

Thorsten

[Guest Andrew Williams]

RE: My DHCP Server is giving out duplicate IP addresses...

 

Turn on DHCP Conflict Detection in DHCP on Windows Server 2003. See the link

below for more information:

 

http://technet2.microsoft.com/windowsserver/en/library/4950c160-33e0-4c7a-a0c8-ece07458699b1033.mspx

 

This will resolve the conflict but not why you are getting the conflict.

Could the other IP address be statically set on the other device on the

network which is in your DHCP range?

 

You could try a 'ping -a <IP ADDRESS>' to resolve the hostname or using

NSLOOKUP. This might give you some idea of which device is causing you the

problem.

 

Andrew

 

 

 

"Kelvin" wrote:

> I'm setting up a new PCs on the network and it is being assigend the same IP

> address as another device on the network.

> I'm running Windows XP SP2 on the workstation and Windows 2003 server...

> Is there some procedure I need to run on my DHCP server?

> Is there a database that needs to be rebuilt?

>

> If I take this new PC off the net work, I can still ping the IP address.

>

> Any help would be appreciated

>

> Kelvin

>

>

>

[Guest Newell White]

RE: My DHCP Server is giving out duplicate IP addresses...

 

1) Use ipconfig /all to determine the IP address of the DHCP server that

assigned the PC's IP address.

 

2) If it is not the server you have configured DHCP on, then clearly you

have a rogue DHCP server. Otherwise, could be a rogue server or a device with

fixed IP (not subscribing to DHCP).

 

3) In either case, exclude this address from the scope of your DHCP server

and reboot the PC to get another IP.

--

Regards,

Newell White

 

 

"Kelvin" wrote:

> I'm setting up a new PCs on the network and it is being assigend the same IP

> address as another device on the network.

> I'm running Windows XP SP2 on the workstation and Windows 2003 server...

> Is there some procedure I need to run on my DHCP server?

> Is there a database that needs to be rebuilt?

>

> If I take this new PC off the net work, I can still ping the IP address.

>

> Any help would be appreciated

>

> Kelvin

>

>

>