Although it is not usually so common, especially when there are no problems with the connection of the router or the modem itself (or the combination of both devices), on certain occasions it is possible that problems arise with the IP address of our Mac .
For example, one of the most common problems is related to the warning “Another device is using your IP”, something that can happen when the router is turned on again, the devices begin to connect to the network, and depending on whether they were already or not turned on, when requesting a certain IP from the router, it assigns an address that was already being used by another device that, at that time, was not connected, but is turned on and, in addition, with the same assigned IP.
Checking the Ethernet configuration of our Mac
The first step we must follow is to verify if the Mac’s Ethernet configuration is correct . To do this, we must click on the Apple icon , which we will normally find located in the upper left corner of the screen, and click on System Preferences .
Once this is done, we must click on Network and check that the Location is in Automatic . If not, we must click on the drop-down menu that we will find next to Location, and choose the Automatic option.
Then, we must click on the Advanced button and click on TCP / IP . Now, we must make sure that the Configure IPv4 option is showing Using DHCP . Again, if not, we must click on this drop-down menu and select this option.
Now we have to make sure that the first line, dedicated to IP Address, shows a certain address. If or so, and for example it shows empty or blank, we must restart the router and wait until the address is displayed.
We must also make sure that Configure IPv6 is also displayed with the Automatically selection. If not, we must select this option. Once done, click on Accept , so that the changes are saved.
Obtaining a new IP address on our Mac
Once we have made sure that the configuration is correct (following the steps that we have indicated in the previous section), it is possible to obtain a new IP address . In this way, we will “force” the router to forget the IP address of our Mac, and provide us with a new address.
To do this, we must go to System Preferences (after clicking on the Apple start icon), Network and Advanced . Now click on the TCP / IP tab, and click on the Renew DHCP lease button. Finally, we click OK so that the changes are saved.
This will help us get the router to provide us with a new IP address, instead of using the old one, so the problem may be solved.
What can we do if the problem is not solved?
In the event that the same message continues to appear, and another device connected to the network continues to use the IP address assigned to our Mac, it would be necessary to turn off and on the Ethernet connection of our Mac to restore the system, or the WiFi connection ( in case we are connected to the Internet wirelessly).
In case we use Ethernet, we must go to the Apple start menu, select System Preferences , click on Network , go to Ethernet (which we can find on the left side of the screen), and click on the gear icon that we will find at the bottom, a drop-down menu will appear where we must select the option Deactivate service . Then, you just have to click again on the option Activate service .
In case we are using WiFi, we can access the Wi-Fi section and click on the Disable Wi-Fi button . To finish, we must now click on the option Activate Wi-Fi .
