ipconfig, short for “Internet Protocol configuration,” is a console application program in some computer operating systems (OSs) that displays all of a system’s current Transmission Control Protocol/Internet Protocol (TCP/IP) network configuration values. It also refreshes the computer’s Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings.

When used on its own, it displays Internet Protocol version 4 (IPv4) and IPv6 addresses, subnet mask, and default gateway for all connected adapters.

Read More about ipconfig

Learn more about the important program, regardless of your OS, in this post.

What Are the Different ipconfig Implementations?

Most OSs have the command’s capabilities even if they differ in terms of implementation.

Microsoft Windows and ReactOS

First off, you should know that ReactOS can be considered an open-source version of Windows.

The command supports the command line switch /all, which results in more detailed information than just ipconfig.

The command also forces a refresh of the DHCP IP address of the host computer since it requests a different IP address. You can do that by using two commands in sequence:

  1. ipconfig /release forces the client to immediately give up its IP address by sending the server a DHCP release notification that updates the status information and marks the IP address as “available.”
  1. ipconfig /renew requests a new IP address.

Note that when the computer is connected to a cable or Digital Subscriber Line (DSL) modem, you should plug it directly into the modem network port to bypass the router before you use ipconfig /release. You must also turn off the power for a while to ensure another computer takes the old IP address.

macOS

The command serves as a wrapper to the IPConfiguration agent that controls the Bootstrap Protocol and DHCP client from the command line interface.

You can release and renew an IP address if it happens to have been assigned incorrectly by the DHCP server during the automated assignment process. As with most Unix-based OSs, macOS uses ifconfig for more direct control over network interfaces like configuring static IP addresses.

What Are the Different ipconfig Parameters?

Like many commands, you can use different parameters with ipconfig.

  • /all: Displays the full TCP/IP configuration for all adapters. In this case, adapters represent physical interfaces like installed network adapters or logical interfaces like Internet connections.
  • /displaydns: Displays the contents of the DNS client resolver cache, including both entries preloaded from the local Hosts file and any recently obtained resource record for name queries the computer resolved. The DNS Client service uses this information to resolve frequently queried names quickly, before querying their configured DNS servers.
  • /flushdns: Flushes and resets the contents of the DNS client resolver cache. During DNS troubleshooting, you can use this to discard negative cache entries, along with any other entry that has been added dynamically.
  • /registerdns: Initiates the manual dynamic registration of DNS names and IP addresses configured on a computer. You can use this to troubleshoot failed DNS name registrations or resolve dynamic update problems between your computer and the DNS server without rebooting. The DNS settings in the advanced properties of TCP/IP determine which names are registered in the DNS.
  • /release [<adapter>]: Sends a DHCPRELEASE message to the DHCP server to release the current DHCP configuration and discard the IP address configuration for either all adapters (if an adapter is not specified) or for a specific adapter if the adapter parameter is included. This parameter disables TCP/IP for adapters configured to obtain an IP address automatically. To specify an adapter name, type the adapter name that appears when you use ipconfig without parameters.
  • /release6[<adapter>]: Sends a DHCPRELEASE message to the DHCPv6 server to release the current DHCP configuration and discard the IPv6 address configuration for either all adapters (if an adapter is not specified) or a specific adapter (if the adapter parameter is included). This disables TCP/IP for adapters configured to obtain an IP address automatically. To specify an adapter name, type the adapter name that appears when you use ipconfig without parameters.
  • /renew [<adapter>]: Renews the DHCP configuration for all adapters (if an adapter is not specified) or a specific adapter (if the adapter parameter is included). This is only available on computers with adapters configured to obtain an IP address automatically. To specify an adapter name, type the adapter name that appears when you use ipconfig without parameters.
  • /renew6 [<adapter>]: Renews DHCPv6 configuration for all adapters (if an adapter is not specified) or a specific adapter (if the adapter parameter is included). This is only available on computers with adapters configured to obtain an IPv6 address automatically. To specify an adapter name, type the adapter name that appears when you use ipconfig without parameters.
  • /setclassid <adapter>[<classID>]: Configures the DHCP class ID for a specified adapter. To set the DHCP class ID for all adapters, use the asterisk (*) wildcard character in place of an adapter. This is only available on computers with adapters configured to obtain an IP address automatically. If a DHCP class ID is not specified, the current class ID is removed.
  • /showclassid <adapter>: Displays the DHCP class ID for a specified adapter. To see the DHCP class ID for all adapters, use the asterisk (*) wildcard character in place of an adapter. This is only available on computers with adapters configured to obtain an IP address automatically.
  • /?: Displays Help on the command prompt.

How Do You Run ipconfig ?

Here are the steps in running the command.

  1. To run the command, open the Command Prompt on Windows or Terminal on Mac.
  2. Type ipconfig and press Enter to display information about each network adapter on your computer, including a virtual private network (VPN) client.
  3. Type ipconfig /all and press Enter to show all the information about your network adapter, including:
  • DHCP enabled: Indicates if your network connection uses DHCP or Static IP Address.
  • IPv4 address: Your computer’s IP address.
  • Default gateway: The router your computer is connected to.
  • DHCP server: The router or server that hands out IP addresses in your network.
  • DNS servers: Servers that translate domain names into IP addresses.
  • Link-local IPv6 address: Your computer’s IPv6 address (often unused).
  • Lease obtained: Date and time when your computer received its IP address.
How to Run ipconfig

What Are the Uses of ipconfig ?

The command has several uses. Apart from basic functions like viewing IP address information and troubleshooting network issues, it also has more advanced functions like blocking scripts and diagnosing VPN problems.

View IP Address Information

A primary use of the command is to display a computer’s current IP information and configuration. This includes its IP address, subnet mask, and default gateway of each active network interface. Running ipconfig alone will provide the following information for each network adapter:

  • Ethernet adapter or wireless adapter name
  • IP address
  • Subnet mask
  • Default gateway
  • DHCP server
  • DNS servers

You can also use ipconfig /all to get more detailed information like a computer adapter’s physical address (MAC address), DHCP lease time, and DNS hostname.

Monitor Network Performance

The command helps monitor network performance by displaying information about the IP addresses and other network settings. It helps identify network bottlenecks, detect connectivity issues, and troubleshoot other network-related problems. You can also use the command to gather information like the IP address, subnet mask, and DNS servers assigned to a network to identify potentially troublesome patterns and trends in network usage.

Automate Tasks

The command in scripts automates network configuration tasks or gathers information about network settings. This is useful in managing a large number of computers and monitoring network performance.

Diagnose VPN Problems

The command can help you view the IP addresses and other network settings of a computer when it is connected to a VPN. This is useful for troubleshooting VPN connectivity issues or identifying the cause of slow VPN performance.

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The command, whether used on its own or with different parameters, has several uses in networking and performance monitoring.

Key Takeaways

  • ipconfig is short for “Internet Protocol configuration.”
  • It is a console application program in some computer OSs that displays all of a system’s current TCP/IP network configuration values.
  • It refreshes a computer’s DHCP and DNS settings.
  • When used on its own, it displays IPv4 and IPv6 addresses, subnet mask, and default gateway for all connected adapters.
  • It enables users to view IP address information, monitor network performance, automate networking tasks, and diagnose VPN problems.

Sources

  • https://en.wikipedia.org/wiki/Ipconfig
  • https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/ipconfig
  • https://www.whatismyip.com/ipconfig/
  • https://attack.mitre.org/software/S0100/