If two devices have the same IP address on one network, they conflict, and one or both lose reliable connectivity. You may see an IP address conflict warning, dropped connections, or pages that will not load. It usually happens when a device is set to a static IP that the router also handed out, or after a router glitch. Fixing it means giving each device a unique address.
Why this happens
An IP address must be unique on a local network so data reaches the right device. When two share one address, the network cannot tell them apart.
The usual causes are a device set to a fixed IP that overlaps with the range the router assigns automatically, or a temporary DHCP glitch after devices reconnect.
Is this normal?
No. It is a misconfiguration or a glitch, not normal operation. It is common, though, and usually easy to clear.
Does it cause any problems?
Expect intermittent or failed connectivity for the affected devices, conflict warnings, and services that stop responding. Once each device has a unique address, everything returns to normal.
How to fix or check it
- Restart the router. This usually reassigns addresses cleanly and clears the conflict.
- Windows: open Command Prompt and run ipconfig /release then ipconfig /renew to get a fresh address.
- Mac: System Settings, Network, select the connection, Details, TCP/IP, then Renew DHCP Lease.
- Phone: turn Wi-Fi off and on, or forget and rejoin the network to request a new address.
- If you use static IPs, make sure each is unique and outside the router's automatic DHCP range, or switch the device back to automatic.
Frequently asked questions
What causes an IP address conflict?
Usually a device set to a static IP that overlaps the router's automatic range, or a DHCP glitch that assigned the same address twice.
How do I stop conflicts from happening again?
Let the router assign addresses automatically where possible, and if you use static IPs, keep each unique and outside the automatic range.
Does an IP conflict affect the whole network?
Mainly the two devices sharing the address. Other devices with unique addresses keep working normally.