Connections

A network tool that lets you obtain information about current TCP/IP connections.

You can use the Connections tool to query detailed listings of all TCP and UDP sockets on your system, including the foreign address and state of TCP connections.

To use the Connections tool, do the following:

1. Select the Connections tab.
   
   The Connections tool displays the results in the Response area.
   
   
2. Set in the Options dialog box any of the options you want to use:
   
   TCP
   
   When this option is checked, the Connections tool queries a list of active sockets for TCP protocol.
   
   UDP
   
   When this option is checked, the Connections tool queries a list of active sockets for UDP protocol.
   
   Host Names
   
   When this option is checked, the Connections tool uses the numeric host address associated with the socket to look up the corresponding symbolic host name.
   
   Port Names
   
   When this option is checked, the Connections tool uses the numeric port number to look up the corresponding symbolic port name.
   
   
3. Click the Refresh button to update the results in the Response area.
   

The possible state values for TCP sockets are as follows:

CLOSED

Closed. The socket is not being used.

LISTENING

Listening for incoming connections.

SYN_SENT

Actively trying to establish connection.

SYN_RECEIVED

Initial synchronization of the connection under way.

ESTABLISHED

Connection has been established.

FIN_WAIT

Socket closed. Shutting down connection.

FIN_WAIT2

Socket closed. Waiting for shutdown from remote.

CLOSE_WAIT

Remote shutdown. Waiting for the socket to close.

CLOSING

Closed, then remote shutdown. Awaiting acknowledgment.

LAST_ACK

Remote shutdown, then closed. Awaiting acknowledgment.

TIME_WAIT

Wait after close for remote shutdown retransmission.

Note:

Looking up the corresponding symbolic host name for each host address can significantly increase the time it takes to complete a query.

Connections example: