You can give a Mac a fixed local IPv4 address by changing the selected network service from automatic DHCP assignment to manual TCP/IP settings. The address, subnet mask, router address, and DNS server must match the network's plan. Choose them before opening the settings; an address that merely looks familiar can conflict with another device or make the Mac unreachable.

On current macOS versions, manual IPv4 settings are available through System Settings, Network, and TCP/IP. The available controls can differ by macOS release and by Wi-Fi or Ethernet service. These settings control an address for the local network. A static public address from an internet provider is a separate service and is not created by this setting.

Plan the Mac's Local Address

Get an unused IPv4 address from the network administrator or the router's allocation plan. Confirm the subnet mask, router or default gateway address, and DNS servers at the same time. Record the Mac's existing TCP/IP and DNS settings so you can restore them later. If the Mac belongs to an organization, follow its device-management rules before changing any network configuration.

For example, a network might use 192.168.20.0/24, a router at 192.168.20.1, and a separately allocated address for the Mac. Those numbers are illustrative only. Your own network may use a different subnet or mask. Do not take the next number after the router without checking the DHCP range and existing reservations. A device that is off today may still have an address allocated to it.

Keep a note of which service you changed, especially if the Mac has both Wi-Fi and Ethernet active. A connection may continue to work through the other service, hiding a mistake in the one you intended to configure. Test on the relevant service and record the network name without exposing private credentials.

Some routers can reserve an address for a particular device while the Mac continues to use DHCP. If you manage the router and only need predictable local addressing, that may be easier to maintain across changes. A manual address stored on the Mac stays in its network service settings and can be unsuitable after moving to a different network.

Configure TCP/IP Manually

Open the Apple menu > System Settings > Network. Select the Wi-Fi or Ethernet service you intend to configure, click Details, then open TCP/IP. In Configure IPv4, choose Manually. Enter the allocated IP address, Subnet mask, and Router values in their respective fields, then apply the change. The Router value identifies the default gateway for destinations beyond the local IPv4 subnet; it is different from a DNS server address, which identifies a server used to resolve names.

The separate Using DHCP with manual address option lets you enter a specific IPv4 address while still using DHCP. Choose the method specified by whoever manages the network rather than switching between methods to guess at working settings.

If the plan provides DNS server addresses, open the DNS pane for the same network service. Add only the approved IPv4 or IPv6 server addresses to the DNS Servers list and save. DNS is configured separately from the TCP/IP address fields. Record any existing manual DNS entries before replacing them, including network-specific search domains if they matter for local services.

Verify Router and DNS Access

Return to the network service details and confirm the Mac displays the planned IPv4 address and router. Check a service on the same local network first, such as the router's management page if you are authorized to use it. Then test an approved external website by name. The stages help distinguish local addressing, gateway routing, and name resolution problems.

If the local router cannot be reached, inspect the selected service, subnet mask, address allocation, and physical or wireless connection. If the router works but outside services do not, check the router address and upstream access. If services fail by name, compare the DNS server list with the values supplied for this network. Testing a website by its numeric address does not reliably isolate DNS because the site may require its hostname to select the right service. A single failed ping or blocked management page is not conclusive because some networks restrict those tests; use a service the network is expected to permit.

Watch for intermittent service or warnings that suggest an address conflict. Stop using a disputed address and confirm the allocation with the administrator. Do not keep trying random addresses or copy values from another network.

Return the Service to DHCP

To undo the manual IPv4 setting, open System Settings > Network, choose the same service, click Details > TCP/IP, and set Configure IPv4 to Using DHCP. Apply the change and confirm an address and router are supplied by the network. Renew DHCP Lease is available when the service uses DHCP. Renewing refreshes the local DHCP configuration and does not guarantee a different public IP address.

Reopen the DNS pane and remove the manual DNS server entries you added if the goal is to return to the network's automatically supplied DNS. Restore any original organization-specific entries according to the recorded settings. Confirm that name-based local and external services work after the rollback. Changing TCP/IP back to DHCP while leaving an unwanted manual DNS entry could make the connection seem partly broken.

If a managed Mac automatically reinstates a configuration, contact its administrator before making further changes.