How do I find a rogue DHCP server on a Cisco switch?

I am having an issue with someone attaching a rogue DHCP server to my network.  I need to find out who is doing this, and so far I have come up with nothing.  I am assuming that I can somehow look at the switch activity when the rogue DHCP server is active to determine which port the traffic is coming from and shut it down, but I not sure what command to use or what to look at to see where the DHCP acks are coming from.
warewolsAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Don JohnstonInstructorCommented:
You could stop from happening in the first place.
http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.1/13ew/configuration/guide/dhcp.html

Once it occurs, you would need to determine the MAC of the DHCP server from the workstation.
"arp -a"

The view the mac address table on the switch.
"show mac-address-table"

That will show you which port the rogue DHCP server is connected to.

0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Switches / Hubs

From novice to tech pro — start learning today.