Windows 7 / Networking

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Nbtstat

Nbtstat (Nbtstat.exe) is a command-line tool for troubleshooting NetBIOS name resolution problems. NetBIOS is a session-layer protocol that formed the foundation of Microsoft network applications for several years. NetBIOS applications identify services on the network by using 16-character NetBIOS names. Each computer on a network might have several different NetBIOS names to identify NetBIOS services on that system.

Today, NetBIOS is implemented on TCP/IP networks by using NetBIOS over TCP/IP (NetBT). NetBT includes its own form of name resolution to resolve NetBIOS names to IP addresses. Names might be resolved by broadcast queries to the local network segment or by queries to a WINS server.

Unfortunately, NetBIOS name resolution is a common source of problems. You can use Nbtstat to reveal the NetBIOS names available on the local computer or remote computers. In troubleshooting scenarios, this helps you to verify that a NetBIOS service is available and its name is being correctly resolved.

To view the NetBIOS name cache, open a command prompt and run the following command.

nbtstat -c

To view the local NetBIOS service names, open a command prompt and run the following command.

nbtstat -n

To view the NetBIOS names on a remote system by using the computer name, open a command prompt and run the following command.

nbtstat -a computername

For example:

nbtstat -a win71

Notice that the output is similar to the output when running nbtstat -n locally. However, this output also displays the remote computer's MAC address. To view the NetBIOS names on a remote system by using the IP address, open a command prompt and run the following command.

nbtstat -A IP_Address

Windows 7 (and all recent versions of Windows) prefers to use DNS host names instead of NetBIOS names. Therefore, if you have an AD DS domain with a DNS server configured, you will rarely need to troubleshoot NetBIOS names. However, Windows might still use NetBIOS names to communicate with computers on the local network and will use NetBIOS names if a host name cannot be resolved with DNS and you have configured a WINS server. To troubleshoot NetBIOS name resolution with WINS servers, use Nblookup, described earlier in this tutorial.