IPCONFIG
IPConfig实用程序和它的等价图形用户界面——Windows 95/98中的WinIPCfg可用于显示当前的TCP/IP配置的设置值。这些信息一般用来检验人工配置的TCP/IP设置是否正确。但是，如果你的计算机和所在的局域网使用了动态主机配置协议（Dynamic Host Configuration Protocol，DHCP--Windows NT下的一种把较少的IP地址分配给较多主机使用的协议，类似于拨号上网的动态IP分配），这个程序所显示的信息也许更加实用。
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"
ipconfig--当使用IPConfig时不带任何参数选项，那么它为每个已经配置了的接口显示IP地址、子网掩码和缺省网关值
ipconfig /all--当使用all选项时，IPConfig能为DNS和WINS服务器显示它已配置且所要使用的附加信息（如IP地址等），并且显示内置于本地网卡中的物理地址（MAC）。
ipconfig /release和ipconfig /renew--这是两个附加选项，只能在向DHCP服务器租用其IP地址的计算机上起作用。如果你输入ipconfig /release，那么所有接口的租用IP地址便重新交付给DHCP服务器（归还IP地址）。如果你输入ipconfig /renew，那么本地计算机便设法与DHCP服务器取得联系，并租用一个IP地址。请注意，大多数情况下网卡将被重新赋予和以前所赋予的相同的IP地址。
如运行IPCONFIG.EXE则运行结果如下:
Windows IP Configuration
Ethernet adapter 本地连接:
Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . : 168.168.120.66
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 168.168.120.250