| ipconfig |
Displays the current TCP/IP settings of the local machine.
ipconfig [/all | /release [adaptername] | [/renew [adaptername] | /flushdns | /displaydns | /registerdns | /showclassid adaptername | /setclassid adaptername [newclassID]]
None
Displays the IP address, subnet mask, and default gateway for each interface on the machine.
/all
Yields verbose output showing additional TCP/IP settings.
/release [adaptername]
Releases an IP address acquired using DHCP. On a multihomed machine, specify an adapter name using the name that appears for the adapter when you type ipconfig without parameters.
/renew [adaptername]
Requests a new IP address from a DHCP server (available only when the computer is configured as a DHCP client)
/displaydns
Displays the contents of the local DNS name cache on the client. When DNS resolves a DNS name into an IP address, the results are temporarily cached.
/flushdns
Flushes the list of locally cached DNS names on the client. Flushing the cache removes these mappings and can be useful when troubleshooting DNS-related problems. Flushing the DNS cache on the client doesn't remove mappings that have been preloaded from the local
Hosts file. (You must remove these mappings from the
Hosts file to do this.)
/registerdns
Causes the client to reregister its hostname with DNS servers without restarting the client machine. This may also be used with Dynamic DNS.
/showclassid
adaptername
Displays all the DHCP class IDs allowed for the adapter. WS2003 DHCP clients support DHCP class options that can be viewed using this command and configured using ipconfig /setclassid.
/setclassid adaptername [newclassID]
Changes the DHCP class ID for the adapter.
Display summary of TCP/IP settings on local machine:
ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : 172.16.11.105 Subnet Mask . . . . . . . . . . . : 255.255.255.0 IP Address. . . . . . . . . . . . : 172.16.11.104 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 172.16.11.196
Display full details:
ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : test Primary DNS Suffix . . . . . . . : mtitcanada.com Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : mtitcanada.com Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek RTL8029(AS) PCI Ethernet Adapter Physical Address. . . . . . . . . : 00-00-B4-A0-47-74 DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 172.16.11.105 Subnet Mask . . . . . . . . . . . : 255.255.255.0 IP Address. . . . . . . . . . . . : 172.16.11.104 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 172.16.11.196 DNS Servers . . . . . . . . . . . : 172.16.11.104 172.16.11.100
Display contents of client DNS name cache:
ipconfig /displaydns Windows IP Configuration localhost. -------------------------------------------------- Record Name . . . . . : localhost Record Type . . . . . : 1 Time To Live . . . . : 31338848 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 127.0.0.1 1.0.0.127.in-addr.arpa. -------------------------------------------------- Record Name . . . . . : 1.0.0.127.in-addr.arpa Record Type . . . . . : 12 Time To Live . . . . : 31338847 Data Length . . . . . : 4 Section . . . . . . . : Answer PTR Record . . . . . : localhost bach.mtitworld.com. -------------------------------------------------- Record Name . . . . . : bach.mtitworld.com Record Type . . . . . : 1 Time To Live . . . . : 261 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 172.16.11.100 test.mtitcanada.com. -------------------------------------------------- Record Name . . . . . : test.mtitcanada.com Record Type . . . . . : 1 Time To Live . . . . : 2665 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 172.16.11.104 Record Name . . . . . : test.mtitcanada.com Record Type . . . . . : 1 Time To Live . . . . : 2665 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 172.16.11.105
Flush client DNS name cache:
ipconfig /flushdns Windows IP Configuration Successfully flushed the DNS Resolver Cache.
Verify that client DNS name cache has been flushed:
ipconfig /displaydns Windows IP Configuration localhost. -------------------------------------------------- Record Name . . . . . : localhost Record Type . . . . . : 1 Time To Live . . . . : 31338835 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 127.0.0.1
Note the mapping that remains in the cache. This is preloaded from the
Hosts file on the client.
Reregister client's DNS information with DNS server:
ipconfig /registerdns Windows IP Configuration Registration of the DNS resource records for all adapters of this computer has been initiated. Any errors will be reported in the Event Viewer in 15 minutes.
Display DHCP class IDs for the client on the "Local-Area Connection" adapter:
ipconfig showclassid "Local Area Connection" Windows IP Configuration DHCP Class ID for Adapter "Local Area Connection": DHCP ClassID Name . . . . . . . . : Default BOOTP Class DHCP ClassID Description . . . . : User class for BOOTP Clients
The DNS name cache in WS2003 also supports negative caching of unresolved or invalid DNS names. However, these negative DNS responses are cached for only a short period of time.
TCP/IP