Windows 2000 IPCONFIG Command Line Parameters

The IPCONFIG utility in Microsoft Windows 2000 is a command-line tool used to display current TCP/IP network configuration values and manage DHCP and DNS client settings. Windows 2000 expanded the utility's capabilities beyond simple IP address display and renewal by introducing switches specifically designed for DNS troubleshooting and DHCP class ID management.

Basic Syntax

ipconfig [/all | /renew [adapter] | /release [adapter] | /flushdns | /displaydns | /registerdns | /showclassid adapter | /setclassid adapter [classid]]

Supported Command-Line Parameters

  • ipconfig (No Parameters) Displays the basic IP address, subnet mask, and default gateway for each bound network adapter.

  • /? Displays the built-in help screen detailing all available switches and usage syntax.

  • /all Produces a full configuration report. This includes the host name, node type, MAC (physical) address, IP routing status, WINS proxy status, DNS servers, DHCP server status, and lease expiration dates for all network adapters.

  • /release [adapter] Sends a DHCPRELEASE message to the DHCP server to release the current IP configuration. If no adapter name is specified, it releases the IP addresses for all bound adapters. Wildcards such as * and ? can be used to match adapter names.

  • /renew [adapter] Sends a DHCPREQUEST message to renew DHCP configuration parameters. If no adapter is specified, it attempts to renew IP addresses for all adapters configured for DHCP.

  • /flushdns Purges and resets the contents of the local DNS client resolver cache. This is commonly used during network troubleshooting to discard invalid or outdated cached DNS entries.

  • /displaydns Displays the contents of the DNS client resolver cache, showing both preloaded entries from the local Hosts file and any recently resolved DNS resource records.

  • /registerdns Refreshes all DHCP leases and re-registers the computer's DNS names with the configured DNS server without requiring a system reboot. This is useful for troubleshooting dynamic DNS (DDNS) registration failures.

  • /showclassid adapter Displays all DHCP class IDs allowed for the specified adapter. The adapter name must be explicitly defined (or specified using wildcards).

  • /setclassid adapter [classid] Configures the DHCP class ID for the specified adapter. If no classid value is specified, the existing class ID is removed.