Failing dhcp exclusion with IP conflict

STSDSE
STSDSE used Ask the Experts™
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Hi All,

I have a new laptop insisting of getting the 192.168.1.60 IP from my DHCP.
Than I get an IP conflict error.
I have check the DNS and only that laptop have this IP. I restarted the DHCP

I have created an exclusion in DHCP for the 192.168.1.60 IP
on the laptop I ran Ipconfig /release
than /flushdns
than /renew.

The laptop still gets the .60 IP.

WHY???

thanks much
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It is possible that it is not getting it from DHCP rather it is statically assigned? Maybe. Check the settings on the nic.
Have you installed a new modem or some device recently, those things sometimes have DHCP as default, so you might have a 2nd DHCP server lurking around, maybe the wireless access point if you are using that.
Commented:
A quick way to solve this would be to statically assign some IP address to the laptop in the network settings - say .61
Reboot the laptop and then revert to dynamic assignment of the IP address using DHCP.  The laptop should then send its DHCP request for .61 which the DHCP will likely honour.

Have you tried disconnecting the laptop from the network and pinging .60 to see if there is actually a machine with that IP address?
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Commented:
If you have multiple DHCP servers giving out IP addresses, this will also sometimes produce an IP confllict.   Eg.  Wireless router with DHCP server turned on as well as a Server 2003 system with DHCP.   Both will give out the next available IP...if it happens to be .60 and they send at the same time, you will experience the conflict.   Turn off DHCP on one of these if this is your situation.

Author

Commented:
No, I do not have multiple DHCP servers.

No, I did not installed a new modem or some device recently.

Cant give it static since it is a remote user who use several IP schema

My biggest question is why (and how to solve) DHCP will give an IP from the exclusion list?!?

Thanks
Well it shouldn't give it out IP addresses in the exclusion list just as it shouldn't give out IP's out of the scope and assign address to conflict.  This is why I thought there was a second DHCP server somewhere.

You could set up a IP reservation by using the MAC address, that should fix it, however if your DHCP server is assigning conflicts, exclusions etc thats worrysome. Does it say anything in the event log.

Author

Commented:
NO, no info on the event log.

We are moving into a new domain forest in the next month or two, with new 2008 servers.

I will try to push static IP to work station.

**** The resolution ***

I changed the IP to other static IP .61 reboot and put it on dhcp again......seems to work so far.

Thanks

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