Manual Pages  — SOCKSTAT

sockstat – list open sockets

SYNOPSIS DESCRIPTION EXAMPLES SEE ALSO HISTORY AUTHORS

sockstat [-46CcfIiLlnqSsUuvw] [-j jail] [-p ports] [-P protocols]

The sockstat command lists open Internet or Unix domain sockets.

The following options are available:

-4
	Show AF_INET (IPv4) sockets.
-6
	Show AF_INET6 (IPv6) sockets.
-C
	Display the congestion control module, if applicable. This is currently only implemented for TCP.
-c
	Show connected sockets.
-f
	Show the FIB number of each socket.
-I
	Show the local address of the socket to which the current socket is spliced, if any. See the setsockopt(2) SO_SPLICE option for more information.
-i
	Display the inp_gencnt.
-j jail
	Show only sockets belonging to the specified jail ID or name.
-L
	Only show Internet sockets if the local and foreign addresses are not in the loopback network prefix 127.0.0.0/8, or do not contain the IPv6 loopback address ::1.
-l
	Show listening sockets.
-n
	Do not resolve numeric UIDs to user names.
-p ports
	Only show Internet sockets if the local or foreign port number is on the specified list. The ports argument is a comma-separated list of port numbers and ranges specified as first and last port separated by a dash.
-P protocols
	Only show sockets of the specified protocols. The protocols argument is a comma-separated list of protocol names, as they are defined in protocols(5).
-q
	Quiet mode, do not print the header line.
-S
	Display the protocol stack, if applicable. This is currently only implemented for TCP.
-s
	Display the protocol state, if applicable. This is currently only implemented for SCTP and TCP.
-U
	Display the remote UDP encapsulation port number, if applicable. This is currently only implemented for SCTP and TCP.
-u
	Show AF_LOCAL (Ux) sockets.
-v
	Verbose mode.
-w
	Use wider field size for displaying addresses.

If neither -4 -, -6 or -u is specified, sockstat will list sockets in all three domains.

If neither -c or -l is specified, sockstat will list both listening and connected sockets.

The information listed for each socket is:

USER	The user who owns the socket.
COMMAND	The command which holds the socket.
PID	The process ID of the command which holds the socket.
FD	The file descriptor number of the socket.
PROTO	The transport protocol associated with the socket for Internet sockets, or the type of socket (stream, datagram, or seqpacket) for Unix sockets.
LOCAL ADDRESS	For Internet sockets, this is the address the local end of the socket is bound to (see getsockname(2)). For bound Unix sockets, socket's filename is printed. For not bound Unix sockets, the field is empty.
FOREIGN ADDRESS	For Internet sockets, this is the address the foreign end of the socket is bound to (see getpeername(2)). For bound Unix sockets a left arrow followed by the peer list is printed. For Unix sockets that went through connect(2) system call a right arrow followed by the peer is printed. Peers are printed in square brackets as [PID FD].
ID	The inp_gencnt if -i is specified (only for TCP or UDP).
ENCAPS	The remote UDP encapsulation port number if -U is specified (only for SCTP or TCP).
PATH STATE	The path state if -s is specified (only for SCTP).
CONN STATE	The connection state if -s is specified (only for SCTP or TCP).
STACK	The protocol stack if -S is specified (only for TCP).
CC	The congestion control if -C is specified (only for TCP).

If a socket is associated with more than one file descriptor, it is shown multiple times. If a socket is not associated with any file descriptor, the first four columns have no meaning.

Show information for IPv4 sockets listening on port 22 using protocol TCP:

$ sockstat -4 -l -P tcp -p 22

Show information for sockets using either TCP or UDP, if neither, the local nor the foreign addresses are in the loopback network:

$ sockstat -L -P tcp,udp

Show TCP IPv6 sockets which are listening and connected (default):

$ sockstat -6 -P tcp

The sockstat command appeared in FreeBSD 3.1 .

The sockstat command and this manual page were written by Dag-Erling Sm/orgrav <Mt des@FreeBSD.org>.