Solved

Rogue DHCP Server Prevention

Posted on 2009-04-01
3
663 Views
Last Modified: 2012-05-06
I am a network engineer for a company as a contractor and have recently been given a new account.  This account has a problem with a rogue DHCP server.  Another DHCP server comes online with an address of 192.168.0.1 and starts handing out phony DHCP leases to all the unsuspecting clients in my active directory.  Now my DC has DHCP setup on it as well, and when it sees this phony DHCP server it says there's another DHCP server on the network and stops the DHCP server service.  This seems to happen every other week for a few hours, then it goes away.  What would be the best solution to finding this rogue device and stopping it from assigning DHCP leases?  And is there a way to configure AD to not shut down the server when it sees the192 server?
0
Comment
Question by:Firefistus
3 Comments
 
LVL 47

Expert Comment

by:dstewartjr
Comment Utility
0
 
LVL 38

Expert Comment

by:ChiefIT
Comment Utility
The above advice is what I would have provided:

However, 192.168.0.1 is usually a router.

For microsoft DHCP servers,  you MUST manuall authorize them to be a DHCP server. Usually rogue DHCP servers are MASS STORAGE devices, (nas servers) or ROUTERS. These devices come default as providing DHCP often.
0
 

Accepted Solution

by:
Firefistus earned 0 total points
Comment Utility
I actually configured my layer 3 switch to block DHCP on all ports except my real DHCP server.  I will see if that takes care of the issue.  Since it only happens on certain days I am going to try to find out who comes into the building that specific day and see if there's a PC or Mac setup to run DHCP.
0

Featured Post

Complete Microsoft Windows PC® & Mac Backup

Backup and recovery solutions to protect all your PCs & Mac– on-premises or in remote locations. Acronis backs up entire PC or Mac with patented reliable disk imaging technology and you will be able to restore workstations to a new, dissimilar hardware in minutes.

Join & Write a Comment

Suggested Solutions

by Batuhan Cetin Within the dynamic life of an IT administrator, we hold many information in our minds like user names, passwords, IDs, phone numbers, incomes, service tags, bills and the order from our wives to buy milk when coming back to home.…
Numerous times I have been asked this questions that what is it that makes my machine log on so slow, there have been cases where computers took 23 minute exactly after taking password and getting to the desktop. Interesting thing was the fact th…
It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages.
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.

771 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

Need Help in Real-Time?

Connect with top rated Experts

7 Experts available now in Live!

Get 1:1 Help Now