Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

DHCP issues

Posted on 2006-11-01
8
Medium Priority
?
209 Views
Last Modified: 2010-04-18
I have a 2003 standard DC with DHCP service running.  My subnet mask is 255.255.255.0.  The problem is that some of my machines are coming up with a subnet mask of 255.255.0.0.  I've been looking at my other servers to see if DHCP services are runnung. Nothing has come up.  I also stopped my DHCP server and rebooted my workstation on the domain and it wasn't assigned IP address so I know that I only have one DHCP server.  Does anyone have a recomendation where I can look further into this issue.  I need to find out where this mask is coming from

Thank you
0
Comment
Question by:jkaminsky
[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
8 Comments
 
LVL 10

Accepted Solution

by:
Seelan Naidoo earned 1000 total points
ID: 17850564
check your network for a bright spark, that may have installed a VM, unintentionally connected to your LAN running DHCP..

I have a few in my team..
0
 

Author Comment

by:jkaminsky
ID: 17850608
Virtual Machine???
0
 
LVL 10

Expert Comment

by:Seelan Naidoo
ID: 17850708
some people set up Virtual Machines on there workstations to get familair with Server operations etc etc..

One of my techs, did this that, but mimic our setup, and as a result we had a rogue DHCP server on our network..

You could run a netdiag from the command prompt..

Maybe you can see which machine is supplying the IP Address..
0
Learn Veeam advantages over legacy backup

Every day, more and more legacy backup customers switch to Veeam. Technologies designed for the client-server era cannot restore any IT service running in the hybrid cloud within seconds. Learn top Veeam advantages over legacy backup and get Veeam for the price of your renewal

 
LVL 14

Expert Comment

by:inbarasan
ID: 17850786
In the system you get the SB 255.255.0.0 , Just do the following
Give IPconfig/all

It will show the DHCP server IP. Check whether it is same DHCP which you are referring. With this you may find problematic DHCP server on your Network
0
 

Author Comment

by:jkaminsky
ID: 17851808
inbarasan

I found a machine with the 255.255.0.0 and it is pointing to my DHCP server which is my DC.  I didn't think of that I will keep trying
0
 
LVL 2

Expert Comment

by:sushibilly
ID: 17856025
What IP address are you getting. Is it in the correct scope?
0
 
LVL 10

Expert Comment

by:Seelan Naidoo
ID: 17856226
Are all your IP addresses for your client machines assigned by your DHCP server..

On the DHCP server, goto the address leases, and check if the machine with the mask of 255.255.0.0 is appearing there..

I
0
 

Author Comment

by:jkaminsky
ID: 17883412
It ended up being the dell switches have a know issue my network guy was able to fix this problem

Thank you to all of your for your help and support
0

Featured Post

Windows Server 2016: All you need to know

Learn about Hyper-V features that increase functionality and usability of Microsoft Windows Server 2016. Also, throughout this eBook, you’ll find some basic PowerShell examples that will help you leverage the scripts in your environments!

Question has a verified solution.

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

Many of us need to configure DHCP server(s) in their environment. We can do that simply via DHCP console on server or using MMC snap-in on each computer with Administrative Tools installed in a network. But what if we have to configure many DHCP ser…
Setting up a Microsoft WSUS update system is free relatively speaking if you have hard disk space and processor capacity.   However, WSUS can be a blessing and a curse. For example, there is nothing worse than approving updates and they just have…
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …
We’ve all felt that sense of false security before—locking down external access to a database or component and feeling like we’ve done all we need to do to secure company data. But that feeling is fleeting. Attacks these days can happen in many w…

722 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