---
title: "IP address conflict on Mac: another device has your address · Kilobat Guides"
url: "https://kilobat.app/guides/ip-address-conflict-mac"
description: "macOS reports that another device uses your Mac's IP address. Find the cause, get a new address from DHCP or correct a manual address."
---

IP, routing and IPv6

# IP address conflict on a Mac

Two devices on one network cannot use the same IP address. macOS checks for a conflict before it uses an address.

Applies to: macOS 13 Ventura and later for the System Settings steps. The Terminal commands work on all current macOS versions. · Checked: 29 October 2026

## Symptoms

- macOS shows a message that another device uses your IP address.
- The connection stops and starts again.
- The problem starts after a new device joins the network.

## Likely causes

- **A manual address that DHCP also gives.** A device with a fixed address inside the DHCP range can take an address that the router gives to the Mac.
- **Two devices with the same manual address.** Someone typed the same address on two devices.
- **Two DHCP servers.** A second router or a hotspot on the same network gives out addresses from the same range.

## How to check

1. Show the service's address and settings.

   ```
   networksetup -getinfo Wi-Fi
   ```
2. List the devices that the Mac has talked to on the local network.

   ```
   arp -a
   ```
3. Show which DHCP server gave the address. Look at the `server_identifier` line.

   ```
   ipconfig getpacket en0
   ```

## How to fix it

1. If the Mac uses DHCP, wait a few minutes. Apple says the DHCP server usually gives the Mac another address.
2. Renew the lease to get a new address now. See [Renew the DHCP lease on a Mac](https://kilobat.app/guides/renew-dhcp-lease-mac).
3. If you typed the address by hand, make sure that it is correct and not in the router's DHCP range.
4. On a managed network, ask the administrator for a free address.
5. Remove or turn off a second DHCP server, such as an extra router in router mode.

## With Kilobat

1. The CLI lists devices from the Mac's neighbor cache, with names that you gave them.

   ```
   kilobat devices
   ```

## Questions

**Can the router reserve an address for my Mac?**

Many routers can. Look for DHCP reservation in the router's settings.

## Sources

- [Apple Support: Resolve IP address conflicts on Mac](https://support.apple.com/guide/mac-help/resolve-ip-address-conflicts-on-mac-mh27606/mac)
- ipconfig(8), man page installed with macOS 27.2
- arp(8), man page installed with macOS 27.2
- [Apple Support: Change TCP/IP settings on Mac](https://support.apple.com/guide/mac-help/change-tcp-ip-settings-on-mac-mchlp2718/mac)

Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with `man <name>` in Terminal.

## Related guides

- [Renew the DHCP lease on a Mac](https://kilobat.app/guides/renew-dhcp-lease-mac): A DHCP lease gives the Mac its IP address, router and DNS servers.
- [Mac has a self-assigned IP address](https://kilobat.app/guides/self-assigned-ip-address): If the Mac gets no answer from a DHCP server, it gives itself a link-local address from 169.254.0.0/16.
- [Find the devices on your local network from a Mac](https://kilobat.app/guides/find-devices-on-network): macOS has two built-in ways to see other devices: the ARP table and Bonjour.
- [See Mac network settings in Terminal](https://kilobat.app/guides/network-settings-terminal): macOS includes command-line tools that show the same network settings as System Settings, and more.