There are a whole list of cmd commands that you can use to test your Network Connections. These commands are available to Windows 2000, XP, Vista, 7, Server 2003 and Server 2008. This commands will be the tools to help setup or know your IP address, DNS, WINS, Subnet mask, Default gateway and other addresses. You can use this commands in the command promt. The command promt (cmd.exe) is the command line interpreter. To use use these commands go to Start-Run or Start search and enter "cmd" to open a Command window.
ping <hostname> - Determine your connectivity to another website.
ipconfig /all - Displays the full TCP/IP configuration for all adapters.
ipconfig /renew - Renews DHCP configuration for all adapters.
ipconfig /release - Discard the IP address configuration.
ipconfig /flushdns - Flushes and resets the contents of the DNS client resolver cache.
ipconfig /displaydns - Displays the contents of the DNS client resolver cache.
ipconfig /registerdns - Dynamic registration for the DNS names and IP addresses that are configured at a computer.
ipconfig /showclassid - Displays the DHCP class ID for a specified adapter.
ipconfig /setclassid <classid> - Configures the DHCP class ID for a specified adapter.
arp - Displays and modifies entries in the Address Resolution Protocol (ARP) cache.
netstat - Displays the active TCP/IP connections and ports.
netsetup.cpl - Easy network install.
hostname - Use the Network Control Panel Applet to set hostname.
route - Displays and modifies the entries in the local IP routing table.
tracert - (traceroute) Show hops as path to another computer.
control netconnections - shortcut to network connections.