Two devices are using the same address. It usually happens when a device has a manually set (static) address inside the range the router hands out automatically. Renewing the computer's address fixes it short-term; moving static devices outside the DHCP range or using reservations fixes it permanently.
Common causes
Static IP inside the DHCP range
A printer or server was given a manual address the router later assigns to another device.
Two DHCP servers
A second router or access point handing out addresses creates duplicates.
Device copied with the same settings
Cloned computers or swapped equipment can carry over the same static address.
How to fix it, step by step
- 1
Renew the computer's address
Run ipconfig /release and ipconfig /renew to get a new address.
- 2
Find devices with static addresses
List printers, servers, cameras, and other devices with manual addresses.
- 3
Separate static and automatic ranges
Keep static addresses outside the router's DHCP range, or shrink the range to leave room.
- 4
Use DHCP reservations
Set printers and servers to automatic and reserve their addresses in the router instead.
- 5
Check for a second DHCP server
Make sure only one device on the network hands out addresses.
When to call a technician
We document every device on your network, plan the addresses, and set reservations so conflicts stop for good.
On-site support across Orange County · see our business networking and WiFi installation services.
Frequently asked questions
What causes IP address conflicts?
Most often a device with a manual address that overlaps the router's automatic range, or a second router handing out addresses.
Can an IP conflict make a printer go offline?
Yes. If another device takes the printer's address, computers send print jobs to the wrong place.
What's a DHCP reservation?
A router setting that always gives a specific device the same address automatically, without a manual setting on the device.