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Nbtstat

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Updated: April 17, 2012

Applies To: Windows Server 2008, Windows Server 2008 R2

Displays NetBIOS over TCP/IP (NetBT) protocol statistics, NetBIOS name tables for both the local computer and remote computers, and the NetBIOS name cache. Nbtstat allows a refresh of the NetBIOS name cache and the names registered with Windows Internet Name Service (WINS). Used without parameters, nbtstat displays help. For examples of how this command can be used, see Examples.

Syntax

Nbtstat [/a <RemoteName>] [/A <IPAddress>] [/c] [/n] [/r] [/R] [/RR] [/s] [/S] [<Interval>]

Parameters

Parameter Description

/a <RemoteName>

Displays the NetBIOS name table of a remote computer, where RemoteName is the NetBIOS computer name of the remote computer. The NetBIOS name table is the list of NetBIOS names that corresponds to NetBIOS applications running on that computer.

/A <IPAddress>

Displays the NetBIOS name table of a remote computer, specified by the IP address (in dotted decimal notation) of the remote computer.

/c

Displays the contents of the NetBIOS name cache, the table of NetBIOS names and their resolved IP addresses.

/n

Displays the NetBIOS name table of the local computer. The status of Registered indicates that the name is registered either by broadcast or with a WINS server.

/r

Displays NetBIOS name resolution statistics. On a computer running Windows XP or Windows Server 2003 that is configured to use WINS, this parameter returns the number of names that have been resolved and registered using broadcast and WINS.

/R

Purges the contents of the NetBIOS name cache and then reloads the #PRE-tagged entries from the Lmhosts file.

/RR

Releases and then refreshes NetBIOS names for the local computer that is registered with WINS servers.

/s

Displays NetBIOS client and server sessions, attempting to convert the destination IP address to a name.

/S

Displays NetBIOS client and server sessions, listing the remote computers by destination IP address only.

<Interval>

Redisplays selected statistics, pausing the number of seconds specified in Interval between each display. Press CTRL+C to stop redisplaying statistics. If this parameter is omitted, nbtstat prints the current configuration information only once.

/?

Displays Help at the command prompt.

Remarks

  • Nbtstat command-line parameters are case-sensitive.

  • The following table describes the column headings that are generated by nbtstat:

    Heading Description

    Input

    The number of bytes received.

    Output

    The number of bytes sent.

    In/Out

    Whether the connection is from the computer (outbound) or from another computer to the local computer (inbound).

    Life

    The remaining time that a name table cache entry will live before it is purged.

    Local Name

    The local NetBIOS name associated with the connection.

    Remote Host

    The name or IP address associated with the remote computer.

    <03>

    The last byte of a NetBIOS name converted to hexadecimal. Each NetBIOS name is 16 characters long. This last byte often has special significance because the same name might be present several times on a computer, differing only in the last byte. For example, <20> is a space in ASCII text.

    Type

    The type of name. A name can either be a unique name or a group name.

    Status

    Whether the NetBIOS service on the remote computer is running (Registered) or a duplicate computer name has registered the same service (Conflict).

    State

    The state of NetBIOS connections.

  • The following table describes the possible NetBIOS connection states:

    State Description

    Connected

    A session has been established.

    Associated

    A connection endpoint has been created and associated with an IP address.

    Listening

    This endpoint is available for an inbound connection.

    Idle

    This endpoint has been opened but cannot receive connections.

    Connecting

    A session is in the connecting phase and the name-to-IP address mapping of the destination is being resolved.

    Accepting

    An inbound session is currently being accepted and will be connected shortly.

    Reconnecting

    A session is trying to reconnect (it failed to connect on the first attempt).

    Outbound

    A session is in the connecting phase and the TCP connection is currently being created.

    Inbound

    An inbound session is in the connecting phase.

    Disconnecting

    A session is in the process of disconnecting.

    Disconnected

    The local computer has issued a disconnect and it is waiting for confirmation from the remote system.

  • This command is available only if the Internet Protocol (TCP/IP) protocol is installed as a component in the properties of a network adapter in Network Connections.

Examples

To display the NetBIOS name table of the remote computer with the NetBIOS computer name of CORP07, type:

btstat /a CORP07

To display the NetBIOS name table of the remote computer assigned the IP address of 10.0.0.99, type:

nbtstat /A 10.0.0.99

To display the NetBIOS name table of the local computer, type:

nbtstat /n

To display the contents of the local computer NetBIOS name cache, type:

nbtstat /c

To purge the NetBIOS name cache and reload the #PRE-tagged entries in the local Lmhosts file, type:

nbtstat /R

To release the NetBIOS names registered with the WINS server and re-register them, type:

nbtstat /RR

To display NetBIOS session statistics by IP address every five seconds, type:

nbtstat /S 5

Additional references