An IP address conflict happens when two devices on the same home network try to use the same local address. One or both devices may lose connection, show a warning, or connect to Wi-Fi without internet.
Does this affect you?
Use this if Windows, Mac, a phone, printer, NAS, smart TV, or camera reports another device is using the same IP address, especially after changing routers or using static IP settings.
Release and renew the affected device
This fixes the immediate conflict by asking the router for a fresh address.
- Windows: open Command Prompt, run ipconfig /release, then run ipconfig /renew. Wait for a new address.
- Mac: open System Settings > Wi-Fi or Network, open Details for the connection, go to TCP/IP, and click Renew DHCP Lease.
- iPhone or Android: turn Wi-Fi off for about 15 seconds, then turn it back on.
After renewing, check whether the error is gone and internet access works normally. If the same device conflicts again soon, continue with the router checks.
Restart the router address table
Use this when multiple devices are affected or the renewal does not last.
- Unplug the router from power for about 30 seconds.
- If you have a separate modem, unplug it too.
- Plug the modem back in first and wait 1 to 2 minutes for stable lights.
- Plug the router back in and wait another 1 to 2 minutes.
- Reconnect affected devices so they all request fresh addresses.
More control
Static IP settings often cause repeat conflicts
Printers, NAS drives, and cameras are common static-IP devices. Replace manual static addresses with DHCP reservations in the router under LAN Setup, DHCP Reservation, or Address Reservation. The router will always give that device the same address without colliding with the normal pool.
Router changes can disturb old addresses
A new router or firmware update may change the DHCP range. A full router restart usually clears old leases after one cycle.
Check for two DHCP servers
If conflicts happen across unrelated devices, you may have an ISP gateway and a separate router both handing out addresses. Put one device into bridge mode so only one router runs DHCP.
Sources
- Microsoft Support – Fix Network Connection Issues in Windows (2025)
- Apple Support – Resolve Wi-Fi and Network Issues on Mac (2025)
- FCC Consumer Guide – Wireless Network Troubleshooting (2024)