Connections is 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 local and foreign addresses and state
of TCP connections. It also reports the icon and
name of the process that owns each socket.
To use the Connections tool, do the following:
Select the Connections tab.
The Connections
tool displays the results in the Response area.
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.
UDP
When this option
is checked, the Connections tool queries a list
of active sockets for UDP.
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.
New connections in color
When this option is checked, the Connections
tool displays new connections in color. A color-selection
dialog box allows you to choose a specific color
value. You can choose a color from either a
set of basic or custom color palettes.
Refresh every [n] sec
When this option is checked, the Connections
tool updates the results in the Response area
every n seconds.
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_RCVD
Initial synchronization
of the connection under way.
ESTABLISHED
Connection has been established.
FIN_WAIT1
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.
DELETE_TCB
Delete TCB.
Tips:
You can right-click the Response area to
display the pop-up menu.
You can disconnect any connection by choosing
Terminate from the pop-up menu.
Note:
Looking
up the corresponding symbolic host name for
each host address can significantly increase
the time it takes to complete a query.
To see icons of system processes you must
run NetInfo with administrative privileges.