0.0.0.0 Is Not a Normal IP Address

What It Means When You See the 0.0.0.0 IP Address

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IP addresses in Internet Protocol (IP) version 4 (IPv4) range from 0.0.0.0 up to 255.255.255.255. The IP address 0.0.0.0 has several special meanings on computer networks. However, it can not be used as a general-purpose device address.

It's easy to confuse 0.0.0.0 and 127.0.0.1 but just remember that an address with four zeros has several defined uses (as described below) while 127.0.0.1 has the one very specific purpose of allowing a device to send messages to itself.

What 0.0.0.0 Means

In short, 0.0.0.0. is a non-routable address that describes an invalid or unknown target. 

This IP address means something different depending on whether it's seen on a client device like a computer or on a server machine.

On Client Computers

PCs and other client devices normally show an address of 0.0.0.0 when they are not connected to a TCP/IP network. A device might give itself this address by default whenever they are offline.

It may also be automatically assigned by DHCP in case of address assignment failures. When set with this address, a device cannot communicate with any other devices on that network.

0.0.0.0 can also theoretically be set as a device's subnet mask rather than its IP address. However, a subnet mask with this value has no practical purpose. Both the IP address and network mask are typically assigned 0.0.0.0 on a client.

On Software Applications and Servers

Some devices, particularly network servers, possess more than one network interface. TCP/IP software applications use 0.0.0.0 as a programming technique to monitor network traffic across all of the IP addresses currently assigned to the interfaces on that multi-homed device.

While connected computers do not use this address, messages carried over IP sometimes include 0.0.0.0 inside the protocol header when the source of the message is unknown.

What to Do When You See the 0.0.0.0 IP Address

If a computer is properly configured for TCP/IP networking yet still shows 0.0.0.0 for an address, try the following to troubleshoot this problem and obtain a valid address:

  • On networks with dynamic address assignment support, release and renew the computer's IP address. Failures with DHCP assignment can be intermittent or persistent. If the failures persist, troubleshoot the DHCP server configuration: Common causes of failure include having no available addresses in the DHCP pool.
  • For networks that require static IP addressing, configure a valid IP address on the computer