IP Address Conflict: What It Means and How to Fix It
"Another device on the network is using your computer's IP address." This alarming little message means two devices on your network ended up with the same address — and since local delivery relies on unique addresses, both devices' connections turn flaky or die. The good news: it's almost always fixable in two minutes.
What causes an IP conflict
- Static meets DHCP — the most common cause. Someone manually set an address inside the router's DHCP pool, and the router later leased that same address to another device.
- A sleeping device returns — a laptop wakes from sleep still claiming a lease the router has since reassigned.
- Two DHCP servers — a second router or extender wired incorrectly, each handing out overlapping addresses.
- Router amnesia — after a reboot or firmware update, the router forgets existing leases and re-issues in-use addresses.
Quick fixes (try in order)
- Toggle the connection — turn Wi-Fi off and on. The device requests a fresh lease and usually receives a different, free address.
- Force a lease renewal —
- Windows:
ipconfig /releasethenipconfig /renew - Mac: System Settings → Network → Details → TCP/IP → Renew DHCP Lease
- Phones: forget the network and rejoin
- Windows:
- Restart the router — clears the lease table and re-issues consistent addresses to everyone.
- Hunt the static culprit — if the conflict recurs, some device has a hard-coded address. Check cameras, printers, NAS boxes and smart-home hubs; move them to DHCP or to an address outside the pool.
Preventing conflicts permanently
- Use DHCP reservations, not device-side statics — reserve fixed addresses in the router so it never double-assigns; see the case for this in our DHCP guide.
- If you must set statics, keep them outside the DHCP range (e.g. pool
.100–.200, statics.2–.50). - One DHCP server only — put secondary routers in access-point/bridge mode.
Note this is purely a local-network issue — your public IP can't conflict with a neighbour's, since ISPs manage those centrally. Two homes both using 192.168.1.5 internally is normal and harmless, as explained in public vs private IPs.
Frequently asked questions
Can an IP conflict damage anything?
No — it just breaks connectivity for the affected devices until resolved. Fix it with a lease renewal or router restart.
Why does the same conflict keep coming back?
A device with a manually configured address inside the DHCP pool. Find it and either switch it to DHCP with a reservation or move it outside the pool.