If you've ever seen the message "Windows has detected an IP address conflict", you may be wondering what that might mean. While IP conflict issues are not usually difficult to fix, they are often confusing, especially for those new to networking.
Let's look at what an IP address conflict is, how it happens, and the steps you need to take to correct this error when it occurs.
What is an IP address conflict?
An IP Conflict occurs when two or more devices on the same network have the same IP address. To explain why this is a problem, we must take a step back and see what are IP addresses.
IP is essentially a unique number of the type xxx.xxx.xxx.xxx (IPv4), where each xxx group is a number from 0 to 255. For example something like 192.168.120.141. This form of an IP is version 4 and is intended for both internal and external IPs. That is, for those that you use in your network but also for those that are used all over the world.
Their number is limited from 0.0.0.0 to 255.255.255.255, ie a total of 4.294.967.296 possible unique addresses, a very small number for the development of the World Wide Web, and for this reason version 6 has been released, which IPs now have the format xxxx: xxxx: xxxx: xxxx: xxxx: xxxx.xxxx (IPv6) and each group receives both letters and numbers so their number can reach the number 3,403 × 1038 unique addresses.
Just as it is a physical home address for receiving mail and (unfortunately) PPC bills, so IP addresses work as a way to locate your computer on a network. Your router uses these IP addresses to direct network traffic to the correct devices.
Due to this system, each IP address cannot be assigned to more than one device. If this happens, the network will be confused by dual IP addresses and will not be able to use them properly.
But since no two computers can have the same IP address, how does the error occur?
How does an IP address conflict occur?
In most cases on modern networks, IP conflicts are rare. This is because of DHCP (Dynamic Host Configuration Protocol), a system used by routers to deliver IP addresses.
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With DHCP, when you connect a new device to your network, your router gives you an available IP address from the group of IPs it has to choose from. The device uses this IP for some time, until the need to use it expires and then if it needs to be used again it has to get a new one. Unless your router is malfunctioning, two devices should never get the same IP address from this system.
Most commonly, IP conflict may occur when you assign static IP addresses to your network. Instead of automatically selecting a DHCP address, you can configure a network device to always use the same IP address that you specify for a specific device. This IP that is always fixed for a specific device is called "static IP address".
On the contrary, the IP addresses that are not fixed and change each time depending on what numbers are available each time free to use, are called "dynamic IP addresses“. If you enter the same static address on two devices incorrectly, you will run a duplicate IP error.
Another IP conflict scenario can occur if you have two DHCP servers on your network (something to avoid). For example, you may have connected your own wireless router to your ISP router. If both devices try to act as routers, they may deliver dual IP addresses.
Finally, you can enter duplicate IPs into the network when a machine returns to it when it is in standby mode. For example, say you leave your laptop idle for two weeks. During this time, the router can retrieve the IP address of the laptop and assign it to another device, such as your phone.
When you turn on the laptop again, it may think it still owns that IP address, resulting in a conflict of IP addresses. This can also happen if you put your computer on another network and you have assigned it a static IP that happens to use the same IP group as yours.
How to resolve an IP address dispute
Like all network troubleshooting solutions, the first step is to restart the troubled computer and networking equipment.
IP address conflict error is a small problem that will resolve a reboot. Restarting the router and / or modem will reset all IP addresses via DHCP.
If restarting all devices does not resolve the issue, then the problem is a little deeper. You should do the next check to see if your computer uses a static IP address.
If you are running Windows, open Settings and go to Network and Internet> Status. Click "Change adapter option" a little further down.
Then, in the window with your connections, double-click the network connection name.
On the resulting screen, click Properties.
Then double-click "Internet Protocol Version 4".
There you should see "Obtain an IP address automatically" selected. If not, select it and press OK. Repeat these steps for Internet Protocol Version 6 and see if the conflict is over.
You should also try unlocking your computer's current IP address and getting a new IP address. Although restarting it usually changes the IP, it is worth trying this technique:
Right-click the Start button and select "Command Prompt" or "Windows PowerShell". Type the following command and press Enter to leave your current IP address:
Then use the following command to obtain a new IP address from the router:
Check your router for conflicting devices
If the above steps do not fix the problem, you should then log in to your router's control panel and take a look at the connected devices. How you do this will depend on the model of your router, so we can not give exact instructions.
Usually in your router menu, you will find a list of connected devices under a section titled Connected Devices or My Network or something similar (Attached Devices, Connected Devices, DHCP Clients, My Network). Take a look at each device and watch out for dual IP addresses.
If you find two devices with the same address, clear the static IP address settings or refresh their IP on your router to resolve the conflict.
Update your router firmware
A faulty router can often cause IP conflicts even without warning. If you still have IP address conflicts even after performing the above troubleshooting, you will need to update your router firmware.
The exact steps for this also depend on the router you have. You will usually find a firmware update option when you log in to your router's control panel. This can be under an advanced menu or something like "Tools" etc.
While some routers allow you to update the firmware automatically through their menu, others require you to download a file from the manufacturer and upload it to your router. Check your router manufacturer's website for more help.
Now you know what an IP address conflict is, how two devices could get the same IP address, and how to fix it. Most of the time, a collision will not occur in the average home network. And if it does, you can usually fix it with a few quick restarts.