Handy diagnostic tools

Windows 2000 carries forward many of Windows NT's familiar TCP/IP diagnostic commands, but the more recent OS also adds several new commands. Whether you're an experienced or novice Win2K administrator, you'll learn a thing or two from this list of top 10 TCP/IP diagnostic commands.

10. Hostname—Hostname is one of the most basic TCP/IP utilities. It displays the name of the system running the command.

C:\>hostname

9. Lpq—The Lpq command displays the status of a remote Line Print Daemon (LPD) print queue. To display the status of a printer named HPLJ4 (identified by the -P switch) on a system named teca4 (identified by the -S switch), enter

C:\>lpq -Steca4 -PHPLJ4

8. Arp—You use the Arp command to view, add, or delete entries in the IP-address-to-physical-network-address translation tables that the Address Resolution Protocol (ARP) uses. To display the cached IP and MAC addresses on your system, enter

C:\>arp —a

7. Ipconfig—The Ipconfig command displays your system's current TCP/IP configuration settings. Ipconfig can also report your current DNS servers' addresses.

C:\>ipconfig /all

6. Netstat—The Netstat command displays your current TCP/IP or UDP connection's status and statistics. Netstat shows both the local and remote name and port of your active network connections. The ? switch displays all the available Netstat switches. To display all active connections in port order, enter:

C:\>netstat -n

5. Route—You can use the Route command to edit or view the IP routing table from the command prompt. Win2K uses the routing table when it needs to find a path to another TCP/IP host. The ? switch displays all the available Route command-line options. To use Route Print to view your system's routing table, enter

C:\>route print

4. Nslookup—The primary command for diagnosing DNS problems, Nslookup is an interactive utility that displays a special command prompt. To display the Nslookup commands, you can enter help at this command prompt. The ls subcommand lists the DNS domain information.

C:\>nslookup

3. Tracert—You use this command to verify that a router path exists between your system and a remote system. Tracert reports the number of hops necessary to reach a given destination. For example, to trace the route to http://www.winnetmag.com, you would enter

C:\>tracert www.winnetmag.com

2. Ping—The Ping command is the most basic TCP/IP network diagnostic tool. If you can't ping a system, you probably won't be able to communicate with that system. To ping a system with the IP address 192.168.100.1, for example, you would enter

C:\>ping 192.168.100.1

1. Pathping—One of Win2K's coolest new TCP/IP tools, Pathping combines the functionality of the Ping and Tracert commands into one handy and robust diagnostic utility. Pathping pings each router between the originating computer and a target destination, then records each hop's duration and packet loss. To use Pathping against http://www.winnetmag.com, enter

C:\>pathping www.winnetmag.com