The following common utilities used to troubleshoot TCP/IP:

• hostname: the hostname command displays the host name of the computer that it is run on.
• ipconfig: the ipconfig command displays the basic TCP/IP settings of all active network connections. The most important items to look for are: host name, IP address, and network mask.
• ping: The ping command is useful for verifying connectivity between two IP devices. The command sends an Internet Control Message Protocol (ICMP) Echo Request message to a remote machine and receives an ICMP Echo Reply message back if the remote device is able to respond. You can ping a computer based on the computer's IPv4 address, IPv6 address, hostname (DNS resolves), or NetBIOS name (WINS resolves).
• tracert: The tracert command details an IP path throgh routers to a destination IP address.
• pathping: The pathping command combines the functionality of the ping and tracert commands.
• route: The route command can alter or display the IP routing table.
• netstat: The netstat command can display different types of TCP/IP statistics for active software and connections.
• nbtstat: NBT is NetBIOS over TCP/IP, and the nbtstat command is used to display TCP/IP connection protocol statistics over NBT.
• getmac: The getmac command identifies the MAC address assigned to each adapter in the system.
• arp: The arp command identifies the MAC address of computers that can directly communicate with the computer by displaying the address resolution protocol (ARP) table.
• netsh: The netsh command is a powerful script tool that can view or modify the computer's network configuration locally or in combination with other tools remotely.
• nslookup: The nslookup command can be used at the command prompt to lookup a DNS entry from a specific DNS server or it can provide an interactive text-based console for advanced DNS queries.