Windows NT 4 includes numerous command-line utilities that can help you troubleshoot network problems. However, while you're more than likely familiar with most of these tools, running into unexpected network issues can sometimes cause your mind to go blank. Here's a quick list of five Windows NT utilities that every administrator should keep in his or her IT toolkit.
IPCONFIG is a basic utility for diagnosing problems with TCP/IP, and it also displays some TCP/IP settings, including IP address, subnet mask, and default gateway. Using the /all switch with IPCONFIG displays additional information, such as DNS servers, physical MAC address, DHCP settings, and more. You can also use the /release and /renew switches to release or renew the IP address lease from the DHCP server.
NBTSTAT displays protocol statistics and current TCP/IP connections using NetBIOS over TCP/IP (NBT). You can also use NBTSTAT to display registered NetBIOS names.
NETSTAT displays even more TCP/IP statistics and connections. If you want to know which ports are open on your machine, enter netstat -a, and the system will return a list of all open protocols and remote connections that are using these ports. You can also display the routing table with netstat -r, or you can view some TCP/IP statistics using netstat -s.
NSLOOKUP is useful if you have problems with DNS servers or you need to manually query DNS servers for host records. Advanced users can also list all records in DNS domains.
PING is the most basic TCP/IP troubleshooting tool. Administrators use it to make sure they've installed the TCP/IP stack correctly and that the network connection works. PING uses ICMP Echo requests and replies, which firewalls can block on some networks. This is why PING times out even when the connection with a remote machine works.