DHCP IP address

I had a DHCP reservervation for a machine I had deleted by accident and another machine took the IP. Is there a way to get that IP back and reserved? 2008 server
Thomas NSystems Analyst - Windows System AdministratorAsked:
Who is Participating?

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

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.

Seth SimmonsSr. Systems AdministratorCommented:
release it (ipconfig /release from elevated command prompt) then reserve your address then ipconfig /renew on the other system to get a new address

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
Thomas GrassiSystems AdministratorCommented:
Add to Seth's answers

after you make your reservation turn on the computer it is for and make sure it obtains the correct address before you do the ipconfig /renew on the other computer

then you should be ok
Will SzymkowskiSenior Solution ArchitectCommented:
You can also exclude this IP completely from your scope. This way if you were to remove a reservation in the future and want to assign it to another machine (say you got a new Laptop) you do not have to risk the chance of it getting it picked up by a DHCP client.

Best practice is to exclude a range of IP's so that you can use them for Reservations if needed.

Creating Active Directory Users from a Text File

If your organization has a need to mass-create AD user accounts, watch this video to see how its done without the need for scripting or other unnecessary complexities.

Hypercat (Deb)Commented:
Will's suggestion is valid, but personally I like using reservations rather than excluded IP addresses, because reservations show up in the DHCP list of addresses whereas excluded IPs don't.

My tip - if you have an IP reserved and the machine/device is going away but you want to make sure that the IP address is available for another reservation in the future, then instead of removing the reservation, simply change the MAC address on the reservation to something invalid.  You can even just use all 0's for the MAC address. This way the reservation stays in place but cannot be used by anything until you set a valid MAC address for it.
Will SzymkowskiSenior Solution ArchitectCommented:
Will's suggestion is valid, but personally I like using reservations rather than excluded IP addresses, because reservations show up in the DHCP list of addresses whereas excluded IPs don't.

I think you missunderstood me. I meant create a block of IP addresses to exclude and STILL create reservations with the IP's that have been excluded. This way you can track in DHCP who has what IP address associated to the MAC address of the NIC and to also avoid the issue the user experienced in this Question.

There is going to be some point where you need to change a reservation, and when you remove that Reservation if it is part of the Scope, then there is potential for it to get picked up by a DHCP client (as i have stated already, and we have seen this behavior based on the users question).  

Create your Exclusions and use the IP's that have been excluded for your Reservations.

Re-create your reservation with the target's mac address.  On the system you don't want to have that IP after the reservation made open command prompt as admin and type in IPCONFIG /RENEW * it should release and renew the IP and it shouldn't get the reserved IP .
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

From novice to tech pro — start learning today.