How to fix an IP address conflict

Posted on August 4, 2009 at 5:37 am

Ever get the following message when turning on your computer or taking it out of sleep mode?

There is an IP address conflict with another system on the network

You may also see a different error message for the same problem:

This IP address is already in use on the network. Please reconfigure a different IP address.

This occurs when two computers on the same LAN network end up with the same IP address. When this occurs, both computers end up not being able to connect to network resources or perform other network operations.

This problem, though rare, can occur because of the following reasons:

Two computers are assigned the same static IP addresses
One computer is assigned a static IP address that falls into the DHCP range for the local network and the same address is assigned to a computer by the DHCP server
A laptop is put into sleep mode and then turned on while connected to another network that uses the same IP address
If you have multiple network adapters, it is possible for a to have an IP address conflict with itself

How to resolve an IP address conflict

There are a few ways you can go about fixing this problem. I’ll start with the simplest and move on.

1. Renew IP Address – You can release and renew the IP address for your computer using the command prompt. Read my previous post on how to renew an IP address.

2. Reconfigure Static IP Address – If your computer is using a static IP address, it is best to try and use a different one in the same subnet. One way to check to make sure the one you are picking is not already being used is to simple ping the IP addresss (ping x.x.x.x).

You can read my previous post on how to change your IP address using the command prompt.

3. Use DHCP – If you don’t need to use a static IP address, it’s best to simply choose DHCP instead of manually configuring the IP address. The server will know which addresses are free and which are taken.

4. Update firmware – In some rare instances, the actual DHCP server can malfunction and assign more than one computer the same IP. In this case, it is best to try and update the firmware on your router.

If you’re still having an IP address conflict, post your problem here and I’ll try to help you out! Enjoy!

» Filed Under Computer Tips

Comments

7 Responses to “How to fix an IP address conflict”

BC said on : August 10th, 2009 at 5:28 pm

So how would you find out if you have multiple network adapters, it is possible for an adapter to have an IP address conflict with itself?

BC said on : August 11th, 2009 at 1:21 pm

Hi, well I tried your steps 1-4 but no joy. There still is a notice about a windows system error – ip conflict. My gut tells me that it’s a “If you have multiple network adapters…” problem. I had a Trendnet wireless PCI card that went bad and in my haste to install the new Linksys wireless PCI card I forgot to uninstall the Trendnet.

I’m connected to the internet with the Linksys PCI card installation was by the book, I’m using Windows to configure the wireless connection (not the Linksys software). I’ve tried the show hidden devices in the Device Manager (set devmgr_show_nonpresent_devices=1) and I found a couple of network adapters that weren’t in use anymore, even an old USB wireless-b stick and I uninstalled them with no problem, but still the message shows up, even on start up before entering my windows logon info. Not sure what to do? This IP address conflict message is getting irritating, please help… -BC

Bakhit said on : October 22nd, 2009 at 2:45 am

What will happen if I have two PCs with same ip addresses in the same LAN? Will they work?
This question has been asked in my exam in the HCU university, and answer is our teacher says that they will work? I am disagree with my teacher, how it can work two PCs with same ip addresses in the same LAN? If any one knows please help me!

Catherine said on : November 11th, 2009 at 11:14 am

Hi. I have a linksys WRT54G v5 router with a Dell laptop using Windows XP. I use DSL modem from att that I have had for years. I also have another laptop Gateway that uses Vista. Last night, my internet was stating on the Gateway that I have limited to no connectivity. It happened before that so I unplugged the modem and router, plugged back in and they worked fine.

Last night, did the same thing except I reset the modem and router after failing for plug in to work. Well now my Dell and Gateway will connect with limited or no connectivity. I can however hook the Dell up with a cable and connect to the internet. I upgraded the firmware on the router. Unplugged, replugged router, modem and then rebooted computer. To no avail. I also release and renew in cmd prompt to no avail. My cable works with correct IP addresses but I cannot get the IP address correct on the wireless adapter (linksys) I use under cmd. It is alway a 169. XX XX number. What can I do? I am at my wits end and linksys won’t help because out of warranty. Thanks so much…

jane kilala said on : November 16th, 2009 at 8:26 am

hi,

I have a problem with IP address conflict. The problem is that when you try to ping an IP address, its request timed out, meaning you cannot ping it, but when you try to assign it to a machine, it says that IP address conflict, that the IP is already used on the network.

Please help.

Thanks,

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