It can display more TCP and state informations than other tools.
.SH OPTIONS
+When no option is used ss displays a list of
+open non-listening TCP sockets that have established connection.
+.TP
These programs follow the usual GNU command line syntax, with long
options starting with two dashes (`-').
A summary of options is included below.
Try to resolve numeric address/ports.
.TP
.B \-a, \-\-all
-Display all sockets.
+Display both listening and non-listening (for TCP this means established connections) sockets.
.TP
.B \-l, \-\-listening
-Display listening sockets.
+Display only listening sockets (these are omitted by default).
.TP
.B \-o, \-\-options
Show timer information.
Display only IP version 6 sockets (alias for -f inet6).
.TP
.B \-0, \-\-packet
-Display PACKET sockets.
+Display PACKET sockets (alias for -f link).
.TP
.B \-t, \-\-tcp
-Display only TCP sockets.
+Display TCP sockets.
.TP
.B \-u, \-\-udp
-Display only UDP sockets.
+Display UDP sockets.
.TP
.B \-d, \-\-dccp
-Display only DCCP sockets.
+Display DCCP sockets.
.TP
.B \-w, \-\-raw
-Display only RAW sockets.
+Display RAW sockets.
.TP
.B \-x, \-\-unix
-Display only Unix domain sockets.
+Display Unix domain sockets (alias for -f unix).
.TP
.B \-f FAMILY, \-\-family=FAMILY
Display sockets of type FAMILY.