MacBook Air on macOS Sequoia Wirelessly Connects to DHCP Server with Two Different MAC Addresses, Getting Two IP Addresses

MacBook Air and macOS Sequoia Wirelessly Connects to DHCP Server with Two Different MAC Addresses: Getting Two IP Addresses

When a MacBook Air running macOS Sequoia is connected to a WiFi router that has a DHCP server, it is expected to receive only one IP address. However, some users have reported that their MacBook Air is receiving two IP addresses instead. This article will explain the possible reasons why this is happening and provide solutions to fix the issue.

Understanding DHCP and MAC Addresses

Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a client-server architecture. A DHCP server typically assigns a unique IP address to each device connected to the network based on its MAC (Media Access Control) address.

A MAC address is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This unique identifier is used by DHCP servers to identify the device and assign it an IP address.

Why is My MacBook Air Receiving Two IP Addresses?

There are several reasons why your MacBook Air may be receiving two IP addresses:

• Duplicate MAC Address: If another device on the network has the same MAC address as your MacBook Air, the DHCP server may assign both devices the same IP address. To prevent this, you need to change the MAC address of one of the devices.
• Multiple NICs: Your MacBook Air may have multiple network interface controllers (NICs), each with its own MAC address. If both NICs are enabled and connected to the same network, the DHCP server may assign each NIC a unique IP address.
• Manual Configuration: If you have manually configured your MacBook Air to use two different IP addresses, it will continue to use both addresses even when connected to a DHCP network.

How to Fix the Issue

To fix the issue of your MacBook Air receiving two IP addresses, you can try the following solutions:

• ifconfig

  : Use the ifconfig command in the Terminal app to check the IP addresses and MAC addresses of all NICs on your MacBook Air. If you find duplicate MAC addresses or multiple NICs, you can disable the extra NICs or change the MAC address of one of them.

• ipconfig

  : Use the ipconfig command in the Terminal app to release and renew the IP address of your MacBook Air. This will force the DHCP server to assign a new IP address to your MacBook Air.

• Reset Network Settings: Resetting the network settings on your MacBook Air will remove any manually configured IP addresses and restore the default network settings. To reset the network settings, go to System Preferences > Network > Advanced > Reset.

References

• Dynamic Host Configuration Protocol (DHCP)
• Media Access Control (MAC) address
• How to Change a MAC Address
• How to Find Your Mac's IP Address