# Networking: Windows has detected an IP address conflict / Duplicate address detected by 00:aa:bb:cc:dd:ee

**Code:** `Windows has detected an IP address conflict` · **Category:** Networking · **Seen on:** Windows, Linux, Networking

Two devices on the same network are using the same IP address, so traffic reaches the wrong one or neither.

## Meaning

Find the second owner with `arp -a` (or `arping -D`) and compare MAC addresses. Fix it by moving the static address outside the DHCP pool, creating a DHCP reservation, or renewing the lease; a laptop waking with an old lease and a printer with a manual IP are classic causes.

## Common causes

- Static IP inside the DHCP pool
- Two devices configured with the same manual IP
- Stale lease on a device that woke up
- Second DHCP server handing out the same range
- VM clone with the same IP

## Quick fix

1. Identify both MACs: `arp -a` / `arping -D -I eth0 192.168.1.50`
2. Move statics out of the pool or add a DHCP reservation
3. Renew the lease: `ipconfig /release` and `/renew`

## Detailed fix by platform

### Windows

1. 

```powershell
arp -a | findstr 192.168.1.50
ipconfig /release && ipconfig /renew
```


## How to diagnose

1. **MAC addresses** — Two for one IP?
2. **Static IP** — Inside DHCP pool?
3. **DHCP** — Single server?

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Source: [WhatIsMyError](https://whatismyerror.com/errors/networking/ip-address-conflict-duplicate-arp)