Solved

clients keep losing dhcp address

Posted on 2014-12-11
3
536 Views
Last Modified: 2014-12-15
We are a Windows 2008 domain environment.
Our dhcp range is 192.168.1.50 to 192.168.1.200 subnet mask of 255.255.255.0

We have basically run out of ip addresses
We changed our subnet mask to 255.255.252.0 which now gave us almost 750 more ip addresses.
We then changed our dhcpk scope to 192.168.0.20 to 192.168.0.240.

After rebooting Windows 7 client the computer did not receive an address.
After an ipconfig /release and renew it received a new address.

After rebooting the clients lose the address again.

Tried multiple clients with same result.

Removed scope and recreated the original scope still using the new subnet mask abd everything works fine.

Is there something needed if dhcp server is 192.168.1.20 but giving out addresses on 192.168.0.x  
All the ip addresses fall within the subnet mask.
Any thoughts are appreciated
0
Comment
Question by:Ekuskowski
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 11

Assisted Solution

by:rharland2009
rharland2009 earned 250 total points
ID: 40494885
Just to clarify, you said after deletion and recreation of the scope you have normal operation, right?
I think the problem may have been with some orphaned info inside the original scope.
Historically, if I've changed the mask on a DHCP box I have to delete and recreate the scope to get normal operation.
0
 
LVL 16

Accepted Solution

by:
vivigatt earned 250 total points
ID: 40496202
Use this site:
http://www.subnet-calculator.com/
I assume that you created a scope of  192.168.0.20 to 192.168.1.240 or even 192.168.0.20 to 192.168.3.240 (and not 192.168.0.20 to 192.168.0.240 as you wrote).
You may envisage that your new scope overlaps with the old one so that existing clients can still use their previous IP addresses. Windows clients will try to reuse such an address (preferred IP address).

These articles might help:
http://superuser.com/questions/470585/how-to-force-windows-7-to-ask-for-a-fresh-ip-address-from-dhcp-server.
http://mikepeth.blogspot.fr/2012/02/windows-dhcp-running-out-of-ips-and.html
 
You could shorten the DHCP lease to a small amount of time, tweak the Cleanup Interval and Grace Period and see if this is any better.

If nothing works, record a trace of a DHCP transaction that is not working (use Wireshark or MS NetMon), filter on UDP 67 and 68 and post the trace, we can then examine it and see what is going wrong...
0
 

Author Closing Comment

by:Ekuskowski
ID: 40501728
I'm accepting these two answers because it gets me in the right direction,  I'm not sure when we are going to try again with the scope change.
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Configuring network clients can be a chore, especially if there are a large number of them or a lot of itinerant users.  DHCP dynamically manages this process, much to the relief of users and administrators alike!
Learn how to PXE Boot both BIOS & UEFI machines with DHCP Policies and Custom Vendor Classes
In this video we outline the Physical Segments view of NetCrunch network monitor. By following this brief how-to video, you will be able to learn how NetCrunch visualizes your network, how granular is the information collected, as well as where to f…
Michael from AdRem Software explains how to view the most utilized and worst performing nodes in your network, by accessing the Top Charts view in NetCrunch network monitor (https://www.adremsoft.com/). Top Charts is a view in which you can set seve…

691 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question