is used to dump socket statistics. It allows showing information similar
to
.IR netstat .
-It can display more TCP and state informations than other tools.
+It can display more TCP and state information than other tools.
.SH OPTIONS
-When no option is used ss displays a list of
-open non-listening sockets (e.g. TCP/UNIX/UDP) that have established connection.
+When no option is used ss displays a list of open non-listening
+sockets (e.g. TCP/UNIX/UDP) that have established connection.
.TP
.B \-h, \-\-help
Show summary of options.
.B \-H, \-\-no-header
Suppress header line.
.TP
+.B \-O, \-\-oneline
+Print each socket's data on a single line.
+.TP
.B \-n, \-\-numeric
-Do not try to resolve service names.
+Do not try to resolve service names. Show exact bandwidth values, instead of human-readable.
.TP
.B \-r, \-\-resolve
Try to resolve numeric address/ports.
.TP
.B \-a, \-\-all
-Display both listening and non-listening (for TCP this means established connections) sockets.
+Display both listening and non-listening (for TCP this means
+established connections) sockets.
.TP
.B \-l, \-\-listening
Display only listening sockets (these are omitted by default).
.TP
.B \-o, \-\-options
-Show timer information. For tcp protocol, the output format is:
+Show timer information. For TCP protocol, the output format is:
.RS
.P
timer:(<timer_name>,<expire_time>,<retrans>)
the name of the timer, there are five kind of timer names:
.RS
.P
-.BR on ": means one of these timers: tcp retrans timer, tcp early retrans timer and tail loss probe timer"
+.B on
+: means one of these timers: TCP retrans timer, TCP early retrans
+timer and tail loss probe timer
.P
.BR keepalive ": tcp keep alive timer"
.P
.P
.TP
.B <retrans>
-how many times the retran occurs
+how many times the retransmission occured
.RE
.TP
.B \-e, \-\-extended
Show socket memory usage. The output format is:
.RS
.P
-skmem:(r<rmem_alloc>,rb<rcv_buf>,t<wmem_alloc>,tb<snd_buf>,f<fwd_alloc>,w<wmem_queued>,o<opt_mem>,bl<back_log>)
+skmem:(r<rmem_alloc>,rb<rcv_buf>,t<wmem_alloc>,tb<snd_buf>,
+.br
+.RS
+.RS
+f<fwd_alloc>,w<wmem_queued>,
+.RE
+.RE
+.br
+.RS
+.RS
+o<opt_mem>,bl<back_log>)
+.RE
+.RE
.P
.TP
.B <rmem_alloc>
.P
.TP
.B <fwd_alloc>
-the memory allocated by the socket as cache, but not used for receiving/sending packet yet. If need memory to send/receive packet, the memory in this cache will be used before allocate additional memory.
+the memory allocated by the socket as cache, but not used for
+receiving/sending packet yet. If need memory to send/receive packet,
+the memory in this cache will be used before allocate additional
+memory.
.P
.TP
.B <wmem_queued>
The memory allocated for sending packet (which has not been sent to layer 3)
.P
.TP
-.B <opt_mem>
+.B <ropt_mem>
The memory used for storing socket option, e.g., the key for TCP MD5 signature
.P
.TP
.B <back_log>
-The memory used for the sk backlog queue. On a process context, if the process is receiving packet, and a new packet is received, it will be put into the sk backlog queue, so it can be received by the process immediately
+The memory used for the sk backlog queue. On a process context, if the
+process is receiving packet, and a new packet is received, it will be
+put into the sk backlog queue, so it can be received by the process
+immediately
.RE
.TP
.B \-p, \-\-processes
.P
.TP
.B wscale:<snd_wscale>:<rcv_wscale>
-if window scale option is used, this field shows the send scale factory and receive scale factory
+if window scale option is used, this field shows the send scale factor
+and receive scale factor
.P
.TP
.B rto:<icsk_rto>
.P
.TP
.B backoff:<icsk_backoff>
-used for exponential backoff re-transmission, the actual re-transmission timeout value is icsk_rto << icsk_backoff
+used for exponential backoff re-transmission, the actual
+re-transmission timeout value is icsk_rto << icsk_backoff
.P
.TP
.B rtt:<rtt>/<rttvar>
-rtt is the average round trip time, rttvar is the mean deviation of rtt, their units are millisecond
+rtt is the average round trip time, rttvar is the mean deviation of
+rtt, their units are millisecond
.P
.TP
.B ato:<ato>
a helper variable for TCP internal auto tuning socket receive buffer
.RE
.TP
+.B \-\-tos
+Show ToS and priority information. Below fields may appear:
+.RS
+.P
+.TP
+.B tos
+IPv4 Type-of-Service byte
+.P
+.TP
+.B tclass
+IPv6 Traffic Class byte
+.P
+.TP
+.B class_id
+Class id set by net_cls cgroup. If class is zero this shows priority
+set by SO_PRIORITY.
+.RE
+.TP
.B \-K, \-\-kill
Attempts to forcibly close sockets. This option displays sockets that are
successfully closed and silently skips sockets that the kernel does not support
summary from various sources. It is useful when amount of sockets is so huge
that parsing /proc/net/tcp is painful.
.TP
+.B \-E, \-\-events
+Continually display sockets as they are destroyed
+.TP
.B \-Z, \-\-context
As the
.B \-p
Switch to the specified network namespace name.
.TP
.B \-b, \-\-bpf
-Show socket BPF filters (only administrators are allowed to get these information).
+Show socket BPF filters (only administrators are allowed to get these
+information).
.TP
.B \-4, \-\-ipv4
Display only IP version 4 sockets (alias for -f inet).
.B \-\-vsock
Display vsock sockets (alias for -f vsock).
.TP
+.B \-\-xdp
+Display XDP sockets (alias for -f xdp).
+.TP
.B \-f FAMILY, \-\-family=FAMILY
-Display sockets of type FAMILY.
-Currently the following families are supported: unix, inet, inet6, link, netlink, vsock.
+Display sockets of type FAMILY. Currently the following families are
+supported: unix, inet, inet6, link, netlink, vsock, xdp.
.TP
.B \-A QUERY, \-\-query=QUERY, \-\-socket=QUERY
List of socket tables to dump, separated by commas. The following identifiers
are understood: all, inet, tcp, udp, raw, unix, packet, netlink, unix_dgram,
unix_stream, unix_seqpacket, packet_raw, packet_dgram, dccp, sctp,
-vsock_stream, vsock_dgram.
+vsock_stream, vsock_dgram, xdp Any item in the list may optionally be
+prefixed by an exclamation mark
+.RB ( ! )
+to exclude that socket table from being dumped.
.TP
.B \-D FILE, \-\-diag=FILE
-Do not display anything, just dump raw information about TCP sockets to FILE after applying filters. If FILE is - stdout is used.
+Do not display anything, just dump raw information about TCP sockets
+to FILE after applying filters. If FILE is - stdout is used.
.TP
.B \-F FILE, \-\-filter=FILE
-Read filter information from FILE.
-Each line of FILE is interpreted like single command line option. If FILE is - stdin is used.
+Read filter information from FILE. Each line of FILE is interpreted
+like single command line option. If FILE is - stdin is used.
.TP
.B FILTER := [ state STATE-FILTER ] [ EXPRESSION ]
Please take a look at the official documentation for details regarding filters.
.SH STATE-FILTER
.B STATE-FILTER
-allows to construct arbitrary set of states to match. Its syntax is sequence of keywords state and exclude followed by identifier of state.
+allows to construct arbitrary set of states to match. Its syntax is
+sequence of keywords state and exclude followed by identifier of
+state.
.TP
Available identifiers are:
Find all local processes connected to X server.
.TP
.B ss -o state fin-wait-1 '( sport = :http or sport = :https )' dst 193.233.7/24
-List all the tcp sockets in state FIN-WAIT-1 for our apache to network 193.233.7/24 and look at their timers.
+List all the tcp sockets in state FIN-WAIT-1 for our apache to network
+193.233.7/24 and look at their timers.
+.TP
+.B ss -a -A 'all,!tcp'
+List sockets in all states from all socket tables but TCP.
.SH SEE ALSO
.BR ip (8),
.br