Ipconfig.exe is included with Windows XP. This utility provides you with diagnostic information related to TCP/IP network configuration. Ipconfig also accepts various Dynamic Host Configuration Protocol (DHCP) commands, allowing a system to update or release its TCP/IP network configuration.
The default (with no parameters specified) is to display only the IP address, subnet mask, and default gateway for each adapter that is bound to TCP/IP.
/? Displays this help message
/all Displays full configuration information
/release Releases the IP address for the specified adapter
/renew Renews the IP address for the specified adapter
/flushdns Purges the DNS Resolver cache
/registerdns Refreshes all DHCP leases and reregisters DNS names
/displaydns Displays the contents of the DNS Resolver Cache
/showclassid Displays all the DHCP ClassIds allowed for the specified adapter
/setclassid Modifies the DHCP ClassId
For /all, Ipconfig displays all of the current TCP/IP configuration values, including the IP address, subnet mask, default gateway, and Windows Internet Naming Service (WINS) and DNS configuration.
For /release and /renew, if no adapter name is specified, the IP address leases for all adapters that are bound to TCP/IP are released or renewed.
For /setclassid, if no ClassId is specified, the ClassId is removed.
Note that the /Release and /Renew options can be used only if the system is configured with DHCP.
ipconfig Show information
ipconfig /all Show detailed information
ipconfig /renew Renew all adapters
ipconfig /renew EL* Renew any connection whose name starts EL
ipconfig /release *Con* Release all matching connections, for example, "Local Area Connection 1" or "Local Area Connection2"