How to get a new IP from DHCP server that's different from existing IP

Question

Running Windows, whenever I try this:

ipconfig /release
net stop dhcp
net start dhcp
ipconfig /renew

I get the old IP address re-assigned except on the first attempt. On the first attempt it gave a new IP. But thereafter it is giving me back my old IP.

Solution

When you delete your new IP address lease with ipconfig /release it's up to the DHCP server to decide what IP address you get when you request a new lease. The DHCP server will assign the "next available" IP address, which could easily be the address you just released.

If you have control of the DHCP server and don't want the same IP address you currently have, your options include:

1. Exclude the unwanted IP address from the pool of available DHCP leases so that the DHCP server won't assign the address.
2. Create a DHCP reservation assigning the address you want to the MAC address of your network adapter.

If you don't have control of the DHCP server, your options then become:

1. Avoid DHCP altogether and assign a static IP address to your network adapter.
2. Try to get another computer on the network to get a lease for the unwanted IP address so the DHCP server cannot assign that to your computer.

Comments

[Bungicasse]

Hey, maybe you're getting handed the first available ip-address every time you ask? Are you on a home or work network? We need more info!

[mtak]

Some DHCP servers have an option to reissue the same IP to the same client if able. The DHCP server might be giving you the same address every time. Check the configuration of the DHCP server.

[Adam Silenko]

look as this: How to change MAC address with batch file on Windows 7

[KaiserPerwez]

I am on a home network. and don't have any access to control DHCP server. @Bungicasse

[Adam Silenko]

dhcp servers can cache leases, if they set to do this, then even he connect another computer to network, he get new ip on new host and old unwonted ip on 1st.

[I say Reinstate Monica]

@AdamSilenko Some DHCP server implementations behave this way, but that doesn't take this option off the table for those that do not cache leases. Good point to keep in mind though.

[KaiserPerwez]

When i reset my Mifi, run CCleaner ,restart my PC and then reconnect, I often get my problem solved.But i don't want it this way. I am just trying to achieve this using only "one PC" without restarting it. And yes,I liked the approach of your answer.