ipconfig is one of the most popular command line utilities. It is a successor of the older ‘winipcfg’ utility and dates back to the introduction of Microsoft Windows NT. Precisely, it fetches crucial information about the IP address of a Windows computer and associated TCP/IP settings.
ipconfig can be used with or without parameters to obtain necessary information about the network. The following options can be utilized for all versions of Windows:
Obtain Basic IP Information – The most straightforward output from ipconfig is the IP address, network mask and the default gateway for all adapters configured for that device.
View Available Command Parameters – In order to display available options support by the command, use the following format:
Display IP information for Available Adapters – To display IP addresses, WINS and DNS information about each of the available adapters on the device, type the following:
Release IP addresses – The command line format to terminate active TCP/IP connections on all or a specific network adapter is as follows:
ipconfig /release “Local Area Connection2” ipconfig /release “Local”
The command format can include either full names of connections, or wildcards.
Renew IP Address – Generally followed by release action, the ‘renew’ parameter re-establishes TCP/IP connections. The following format can be used to renew an IP connection which has DHCP enabled:
Some of the functions that can be accomplished with the ipconfig utility for newer Windows versions after the Windows 2000 version include:
Managing DHCP Class Identifiers – Network administrators involved in managing business networks define DHCP classes as identifiers on a DHCP server. This helps them enable clients with the desired settings and preferences for that network as follows:
ipconfig /showclassid ipconfig /setclassid
Options Available for DNS configuration – ipconfig can be used to view the DNS cache available locally. The DNS cache picks up remote server addresses through routine DNS lookups that happen when you visit Web sites, FTP servers, and other remote servers.
DNS cache entries are helpful in improving the performance of your browsers or during advanced troubleshooting issues. DNS caches ensure that you can access websites quickly by storing the right information about the IP address, email server, name or address of the site. However, you might need to manually clear and refresh the DNS cache at times, before an automatic refresh takes place to access the server on a need basis.
The different options used to view and clear DNS cache contents are enlisted below:
ipconfig /displaydns – Displays contents of DNS cache ipconfig /flushdns – Clears DNS cache
Update DNS Settings – You have the option of updating DNS settings on your computer by initiating communication with the DNS server and the DHCP server. Registering the DNS settings manually is an excellent way to troubleshoot potential problems related to the Internet Service provider (ISP) settings.
Troubleshooting can be done for a specific adapter or all adapters, and mainly used in getting a dynamic IP from the ISP’s DNS. The command is used as follows:
The ipconfig is an indispensable utility which enables you to perform a wide variety of IP related operations, from merely refreshing your computer’s IP address to configuring remote servers, from a single command line interface.