Command Reference for IPCONFIG MS-DOS

Ipconfig is a MS-DOS command-line tool used to display and manage the network settings of your computer. Ipconfig is available on Windows machines, and it displays the current network connection details and dhcp client settings.

Ipconfig is an external MS-DOS command, and is available on Windows 95, Windows 98, ME, NT, 2000, XP and Windows Vista Operating Systems. On Windows 9x machines, a graphical tools such as "winipconfig" or "winipcfg" may be used instead. On Linux machine, the if configcommand performs equivalent function.

C:\> ipconfig /?

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

where
    adapter         Connection name
                   (wildcard characters * and ? allowed, see examples)

    Options:
       /?           Display this help message
       /all         Display full configuration information.
       /release     Release the IP address for the specified adapter.
       /renew       Renew the IP address for the specified adapter.
       /flushdns    Purges the DNS Resolver cache.
       /registerdns Refreshes all DHCP leases and re-registers DNS names
       /displaydns  Display the contents of the DNS Resolver Cache.
       /showclassid Displays all the dhcp class IDs allowed for adapter.
       /setclassid  Modifies the dhcp class id.

The default is to display only the IP address, subnet mask and
default gateway for each adapter bound to TCP/IP.

For Release and Renew, if no adapter name is specified, then the IP address
leases for all adapters bound to TCP/IP will be released or renewed.

For Setclassid, if no ClassId is specified, then the ClassId is removed.

Examples:
    > ipconfig                                  ... Show information.
    > ipconfig /all                             ... Show detailed information
    > ipconfig /renew                       ... renew all adapters
    > ipconfig /renew EL*                 ... renew any connection that has its
                                                        name starting with EL
    > ipconfig /release *Con*             ... release all matching connections,
                                                        eg. "Local Area Connection 1" or
                                                              "Local Area Connection 2"

C:\>ipconfig /all

Windows IP Configuration

        Host Name . . . . . . . . . . . . : topwebhosts
        Primary Dns Suffix  . . . . . . . :
        Node Type . . . . . . . . . . . . : Hybrid
        IP Routing Enabled. . . . . . . . : No
        WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Wireless Network Connection:

        Connection-specific DNS Suffix  . :
        Description . . . . . . . . . . . : Intel(R) PRO/Wireless LAN 2100 3B Mini PCI Adapter
        Physical Address. . . . . . . . . : 00-0C-F1-65-5B-70
        Dhcp Enabled. . . . . . . . . . . : Yes
        Autoconfiguration Enabled . . . . : Yes
        IP Address. . . . . . . . . . . . : 192.168.1.100
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . : 192.168.1.1
        DHCP Server . . . . . . . . . . . : 192.168.1.1
        DNS Servers . . . . . . . . . . . : 192.168.1.1
        Lease Obtained. . . . . . . . . . : Thursday, February 08, 2007 2:27:17 PM
        Lease Expires . . . . . . . . . . : Thursday, February 15, 2007 2:27:17 PM

Ethernet adapter Local Area Connection:

        Media State . . . . . . . . . . . : Media disconnected
        Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Mobile Connection

        Physical Address. . . . . . . . . : 00-0D-60-FB-4E-E9

To learn the names of ethernet adapters that you can optionally specify with "ipconfig" command, you may simply type ipconfig command by itself. The command output displays all adapters by name that are available on your computer: e.g. "Local Area Connection", "Wireless Network Connection".
Ipconfig command is most often used to diagnose network problem on a Windows machine. If you're using DHCP, you may try releasing and renewing IP address by performing "ipconfig /release" and "ipconfig /renew" commands shown below.

C:\> ipconfig /release
Windows IP Configuration

No operation can be performed on Local Area Connection while it has its media disconnected.

Ethernet adapter Wireless Network Connection:

        Connection-specific DNS Suffix  . :
        IP Address. . . . . . . . . . . . : 0.0.0.0
        Subnet Mask . . . . . . . . . . . : 0.0.0.0
        Default Gateway . . . . . . . . . :

Ethernet adapter Local Area Connection:

        Media State . . . . . . . . . . . : Media disconnected

C:\> ipconfig /renew

Windows IP Configuration

Ethernet adapter Wireless Network Connection:

        Connection-specific DNS Suffix  . :
        IP Address. . . . . . . . . . . . : 192.168.1.100
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . : 192.168.1.1

To workaround DNS caching issue, you may perform "ipconfig /flushdns" to clear DNS cache value on your computer. DNS uses TTL (Time-To-Live) value which let the intermediate name servers to cache DNS information. If you changed your DNS settings, and your computer doesn't see the change immediately, you may perform "ipconfig /flushdns" to clear the DNS cache.
C:\> ipconfig /flushdns

Windows IP Configuration

Successfully flushed the DNS Resolver Cache.