IP Address Conflict at Home? How to Fix It for Good

You've connected everything to the router, it was all working, and then a warning pops up. On Windows it says "Windows has detected an IP address conflict". On a Mac it reads "Another device on the network is using your computer's IP address", followed by advice to make sure the address is unique. On some printers, games consoles and smart TVs you'll simply see "IP address conflict" or "duplicate IP", and the device drops off the internet.

It's one of the most common home network faults we see, and the good news is that it's almost always fixable in a few minutes. This guide explains what's going on and how to stop it coming back.

Why This Happens

Every device on your home network needs its own address, a bit like a house number on a street. Your broadband router normally acts as the "postman" that hands out those numbers automatically. This system is called DHCP, and on most UK routers the addresses look like 192.168.1.x (BT, EE, TalkTalk, Vodafone) or 192.168.0.x (Sky and Virgin Media).

A conflict happens when two devices end up with the same number. The usual causes are:

• A device with a static IP. Someone (perhaps an installer, years ago) typed a fixed address into a printer, CCTV recorder or computer. The router doesn't know about it and later gives the same address to something else.
• Two devices handing out addresses. An old router, a Wi-Fi extender or a mesh system plugged in behind your main hub can run its own DHCP service, so two "postmen" hand out the same numbers.
• A new router with a long memory on your devices. After a router swap or reset, a device that has been asleep wakes up and keeps using its old address, which the new router has already given away.
• A device that came back from sleep. Laptops and phones sometimes hold on to an address after their lease has expired.
• Older or buggy devices that don't handle DHCP properly, such as very old printers or network storage drives.

Fix 1: Restart in the Right Order

Order matters, because you want the router to be ready before devices ask it for addresses.

1. Turn off the device showing the error.
2. Turn off your router (and any extenders or mesh units) at the plug for 30 seconds.
3. Turn the router back on and wait until its light is solid, usually two to three minutes. On BT hubs that's blue, on Virgin Media hubs it's white or green depending on the model.
4. Turn on any extenders or mesh units and wait a further minute.
5. Turn the device back on.

This clears the router's address list and fixes most one-off conflicts. If the warning returns within a day or two, something is causing it, so carry on.

Fix 2: Release and Renew the Address

You can ask a device to give back its address and request a new one without restarting anything.

Windows 10 and 11:

1. Press the Start button, type cmd and open Command Prompt.
2. Type ipconfig /release and press Enter. You'll briefly lose connection.
3. Type ipconfig /renew and press Enter.
4. Optionally, type ipconfig /flushdns to clear old lookups too.

Mac: open System Settings > Wi-Fi (or Network for a cable), click Details next to your network, choose TCP/IP and click Renew DHCP Lease.

iPhone and iPad: go to Settings > Wi-Fi, tap the blue i next to your network and tap Renew Lease.

Android: the simplest way is to turn Wi-Fi off and on again, or tap your network and choose Forget, then reconnect.

Fix 3: Find and Remove Static IP Addresses

If the conflict keeps returning, a device with a manually set address is the most likely culprit. Check each of these is set to obtain its address automatically:

• Windows 11: Settings > Network & internet > Wi-Fi (or Ethernet), then your network's properties. Next to IP assignment, click Edit and choose Automatic (DHCP).
• Mac: in the same TCP/IP screen as above, set Configure IPv4 to Using DHCP.
• iPhone and iPad: in the network's i screen, make sure Configure IP says Automatic.
• Printers: look in the printer's network or Wi-Fi settings menu (or its web page) for a setting called IP mode, TCP/IP or IPv4 configuration, and set it to Automatic, DHCP or Auto.
• CCTV recorders, network drives, smart home hubs and games consoles: check their network settings for anything marked Manual or Static.

Fix 4: Use a DHCP Reservation Instead

A DHCP reservation tells the router to always give the same address to a particular device. You get the reliability of a fixed address without the risk of a clash, because the router is in charge of it.

1. Log in to your router from a browser on a connected device:
   • BT Smart Hub, Smart Hub 2 and EE Smart Hub: 192.168.1.254. The admin password is printed on the card or sticker on the back of the hub.
   • Sky Hub: 192.168.0.1. The login details are on the sticker on the hub.
   • Virgin Media Hub 3, 4 and 5: 192.168.0.1. The settings password is on the sticker on the hub.
   • TalkTalk and Vodafone: usually 192.168.1.1, but check the sticker.
2. Look for a section called DHCP, LAN settings, IP address allocation or My network. Menus vary by model and change with updates.
3. Find the device in the list of connected devices and choose an option such as Always use this IP address, Reserve or Add reservation.
4. Restart the device so it picks up the reserved address.

Some providers, including BT and Virgin Media, also offer an app that shows connected devices, which helps you identify what's what.

Fix 5: Make Sure Only One Device Hands Out Addresses

This is the cause people most often miss. If you've added an old router to boost the signal, or set up a mesh system or extender behind your provider's hub, it may be running its own DHCP service.

• Old router used as a booster: log in to it and turn off its DHCP server, or replace it with proper kit.
• Mesh systems (Eero, Deco, Google Nest, Orbi): if they sit behind your ISP hub, switch them to bridge or access point mode in their app. Alternatively, put your ISP hub into modem mode where supported (Virgin Media hubs have this) and let the mesh do the routing.
• Extenders: most behave correctly out of the box, but if yours has a router mode, make sure it's set to extender, repeater or access point mode.

Our guide to setting up mesh Wi-Fi with a Virgin, BT or Sky hub walks through this step by step.

Fix 6: Deal With Old or Faulty Devices

If you've done all of the above and one particular device keeps clashing, it may simply be old. Update its firmware if you can. If it's a very old printer or network drive that no longer receives updates, giving it a DHCP reservation usually solves it. If not, it may be time to replace it.

When to Get Help

If conflicts keep returning, you've got a mix of mesh units, extenders and old routers, or there's a CCTV system or network drive you're nervous about touching, we can sort it. Our home Wi-Fi and networking service tidies up the whole network so every device gets a sensible address and one router is in charge. Many problems can be fixed through remote support anywhere in the UK, and Senri Home engineers visit across West and South West London seven days a week, 8am to 9pm. Book a visit or call or WhatsApp 07826 399715.

Related Reading

• Wi-Fi Connected but No Internet? How to Fix It
• Printer Says Offline? How to Fix It on Windows and Mac
• Mesh Wi-Fi With a Virgin, BT or Sky Hub