Fix Self-Assigned IP Address Issue On Mac

Fix Self-Assigned IP Address Issue on Mac

Since the second part of 1900, when the internet was first introduced to us, the way we live our daily life changed irreversibly. It has immensely impacted our culture and commerce. The rise of instant communication by instant messaging, emails, VoIP (Voice over Internet Protocol), and interactive video calls drastically change how we socialize with each other. With the invention of the World Wide Web, commonly known as the Web, and with the emergence of discussion forums, blogs, social networking services, online shopping sites, and search engines, that lets us access a broad range of information and data.

Now the internet has become a part of our daily lives that we can't imagine living without it as it provides us information that we need and lets us communicate with people instantly. It also has a massive influence on businesses. It enables companies to reach a broader audience through social media and online ads displayed on various websites, attract more customers, and increase profit.

Fix Self-Assigned IP Address Issue on Mac

So when you don't have access to the internet, it can be very frustrating for everyone. Especially if it negatively impacts your work. If your Mac can't connect to the internet, you won't be able to access any servers that use an internet connection. Unfortunately, you can't know when the problem will occur. One minute everything can be just fine, and the next thing you see that your Mac doesn't connect to the internet. Instead, the system has a self-assigned IP address. This issue can occur when the user made major configuration changes to the system. The changes can be updating the macOS version, upgrading to a new version, switching to a new system, or restoring the whole system from a backup. When performing these kinds of configurations, settings might not migrate properly, creating problems.

OS issues a self-assigned IP address to allow a network interface to create an ad-hoc network if needed. The ad-hoc network is a temporary type of LAN (Local Area Network) network. The system can create an ad-hoc network only if the network ports detect a proper hardware connection but can't communicate with the DHCP (Dynamic Host Configuration Protocol) server to obtain an IP address. Usually, the issue lies with configuration problems with the system's Firewall, which seems to be particularly vulnerable.

Ethernet users can also experience such a problem. Your Mac might connect to the Wi-Fi perfectly fine, but your Ethernet can run into issues as well. If in network settings, you see a message saying that "Ethernet has a self-assigned IP address and will not be able to connect to the internet," it means that the issue is a failure of DHCP on the cabled connection.

It seems that the DHCP server is the cause of this issue. Let's find out more about what DHCP is to understand better what we're dealing with.

As previously mentions, it's a Dynamic Host Configuration Protocol or, in other words, a network protocol used on Internet Protocol (IP) networks where DHCP server automatically assigns an IP address and other network configuration parameters to each host on the system so they can communicate efficiently with other IP networks. When the DHCP server is not found, a computer or other device on the network needs to be manually assigned an IP address or give itself an APIPA (Automatic Private IP Addressing) address.

DHCP is needed to make the management of IP addresses on networks easier. Manually assigning IP addresses can be confusing. Most users could not locate the IP address information on a computer and assign it themselves, and manually configuring IP addresses would likely lead to errors. That's why automating this process with DHC makes life easier for the network administrator and the users.

DHCP has six components, and all of them are very important. The first component is the DHCP server. It holds IP addresses and related configuration information. Typically it's a router or a server, but can be anything that acts as a host.

The second component is a DHCP client. It's an endpoint that receives information from a DHCP server. This endpoint can be a mobile device, a computer, or anything else that requires connectivity to the internet.

Another component is the IP address pool that's a range of available addresses to DHCP clients.

Subnet is the fourth component of DHCP. Subnet is a segment of IP networks that can be divided into parts.

Another component is a Lease. It's the length of time when a DHCP client holds the IP address information. The client must renew the lease when it expires.

And the last component is the DHCP relay agent. It's a host or a router that listens for client messages transmitted on the network and forwards them to a configured serves. That server then sends the response back to the relay agent that passes them along to the client.

Now that we have some understanding of what a DHCP is, we can proceed to solve the problem. Below you'll find various methods that will show you step by step how you can fix the issue with a self-assigned IP address on your Mac.

Table of Contents:

Check Your Network Preferences

First, you'll need to check TCP/IP settings.

1. Click on the Apple logo in the menu bar.
2. Go to "System Preferences."
3. Find and go to Network settings.

To to Network

4. Click on the "Advanced" button.

Go to Advanced settings

5. Go to the TCP/IP tab.
 
If you see that Configure iPv4 is set to Using DHCP but Router is not set with any IP address, try the following method to fix the problem.

Check Network Preferences

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Reset Network Configuration

This method will reset your network configurations.

1. Launch Finder.
2. In the menu bar, click on "Go" and then click on "Go to Folder."

To to Go To Folder

3. In the pop-up window enter the line: /Library/Preferences/SystemConfiguration/

Go to System Configurations

4. Delete these files:

com.apple.airport.preferences.plist
Networkinterface.plist
preferences.plist

Delete these files

5. Shut down your Mac and then power it back on.
6. Log in and connect your Wi-Fi.
7. Go to the TCP/IP setting again and check if the Router has an

Network connected

After your Mac restarts, it should recreate the files that you deleted.

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Renew DHCP Lease

Try renewing your DHCP lease on your Mac.

1. Click on the Apple logo in the menu bar.
2. Go to "System Preferences."
3. Find and go to "Network" settings.

Go to Network settings

4. Select your Wi-Fi or Ethernet if it's not selected automatically.
5. Click on the "Advanced" button.

Go to Advanced settings

6. Go to the TCP/IP tab.
7. Next to IPv4 Address line, find and click on the "Renew DHCP Lease" button.

renew-dhcp-lease

8. Click on "OK."

After the lease is renewed, check if you're able to connect to your network.

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Create New Network Location

If renewing the DHCP leas didn't help, try creating a New Network Location and then renew the lease.

1. Click on the Apple logo in the menu bar.
2. Go to "System Preferences."
3. Find and go to "Network" settings.

Go to Network

4. Next to "Location", click on the drop-down menu.

Go to Location drop down menu

5. Click on "Edit Locations."

Edit Location

6. Click on the + icon to add New Location.
7. Type in the name for the New Network Location.
8. Click on "Done."

Create New Location

9. Select your Wi-Fi or Ethernet if it's not selected automatically.
10. Click on the "Advanced" button.
11. Go to the TCP/IP tab.
12. Next to IPv4 Address line, find and click on the "Renew DHCP Lease" button.

Renew DHCP Lease

13. Click on "OK."

After the lease is renewed, check if you're able to connect to your network.

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Reset The Firewall

As mentioned before, if you did any configuration changes to the system, your Mac's Firewall might have experienced configuration issues. Try to fix the problem by resetting the Firewall.

1. Launch Finder.
2. In the menu bar, click on "Go" and then click on "Go to Folder."

Go to Go To Folder

3. In the pop-up window, enter in: /Macintosh HD/Library/Preferences/

Go to Macintosh HD Peferences

4. Delete file: com.apple.alf.plist

Reset Firewall by deleting file

5. Shut down your Mac and then power it back on.

After the system boots, if you are asked to allow access to numerous programs and services, choose depending on your preferences and then try to connect to your network.

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Set Service Order

You can try to set the interface order that connects to the internet.

1. Click on the Apple logo in the menu bar.
2. Go to "System Preferences."
3. Find and go to "Network" settings.

Go to Network

4. Click on the gear icon at the bottom next to the + and - buttons.

Click on the Gear icon

5. Click on "Set Service Order."

Set Service Order

6. Drag services to the top of the list.

Drag services to Set Service Order

If you're using Wi-Fi, select the Wi-Fi and drag it to the top.

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Change DNS Servers

Try changing the DNS servers.

1. Click on the Apple logo in the menu bar.
2. Go to "System Preferences."
3. Find and go to "Network" settings.

Go to Network

4. Select your Wi-Fi or Ethernet if it's not selected automatically.
5. Click on the "Advanced" button.
6. Go to the "DNS" tab.
7. Click on the + icon.

Go to DNS tab

8. Add these numbers:

  • 8.8.8.8
  • 8.8.4.4
  • 1.1.1.1
  • 9.9.9.9

9. Click on "OK."

Add DNS servers

If you're still having problems, please contact the Apple Support team.

If any of these methods helped, let us know in the comments!

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About the author:

Tomas Meskauskas

I am passionate about computer security and technology. I have an experience of 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an editor for pcrisk.com since 2010. Follow me on Twitter to stay informed about the latest tech news or online security threats. Contact Tomas Meskauskas.

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