NAME | SYNOPSIS | NOTES | DESCRIPTION | OPTIONS | OUTPUT | FILES | SEE ALSO | BUGS | AUTHORS | COLOPHON

NETSTAT(8)           Linux System Administrator's Manual          NETSTAT(8)

NAME         top

       netstat  -  Print network connections, routing tables, interface sta‐
       tistics, masquerade connections, and multicast memberships

SYNOPSIS         top

       netstat [address_family_options] [--tcp|-t] [--udp|-u] [--udplite|-U]
       [--sctp|-S] [--raw|-w] [--l2cap|-2] [--rfcomm|-f] [--listening|-l]
       [--all|-a] [--numeric|-n] [--numeric-hosts] [--numeric-ports]
       [--numeric-users] [--symbolic|-N] [--extend|-e[--extend|-e]]
       [--timers|-o] [--program|-p] [--verbose|-v] [--continuous|-c]
       [--wide|-W]
       netstat {--route|-r} [address_family_options]
       [--extend|-e[--extend|-e]] [--verbose|-v] [--numeric|-n]
       [--numeric-hosts] [--numeric-ports] [--numeric-users]
       [--continuous|-c]
       netstat {--interfaces|-i} [--all|-a] [--extend|-e[--extend|-e]]
       [--verbose|-v] [--program|-p] [--numeric|-n] [--numeric-hosts]
       [--numeric-ports] [--numeric-users] [--continuous|-c]
       netstat {--groups|-g} [--numeric|-n] [--numeric-hosts]
       [--numeric-ports] [--numeric-users] [--continuous|-c]
       netstat {--masquerade|-M} [--extend|-e] [--numeric|-n]
       [--numeric-hosts] [--numeric-ports] [--numeric-users]
       [--continuous|-c]
       netstat {--statistics|-s} [--tcp|-t] [--udp|-u] [--udplite|-U]
       [--sctp|-S] [--raw|-w]
       netstat {--version|-V}
       netstat {--help|-h}
       address_family_options:
       [-4|--inet] [-6|--inet6]
       [--protocol={inet,inet6,unix,ipx,ax25,netrom,ddp,bluetooth, ... } ]
       [--unix|-x] [--inet|--ip|--tcpip] [--ax25] [--x25] [--rose] [--ash]
       [--bluetooth] [--ipx] [--netrom] [--ddp|--appletalk] [--econet|--ec]

NOTES         top

       This program is mostly obsolete.  Replacement for netstat is ss.
       Replacement for netstat -r is ip route.  Replacement for netstat -i
       is ip -s link.  Replacement for netstat -g is ip maddr.

DESCRIPTION         top

       Netstat prints information about the Linux networking subsystem.  The
       type of information printed is controlled by the first argument, as
       follows:
   (none)
       By default, netstat displays a list of open sockets.  If you don't
       specify any address families, then the active sockets of all
       configured address families will be printed.
   --route, -r
       Display the kernel routing tables. See the description in route(8)
       for details.  netstat -r and route -e produce the same output.
   --groups, -g
       Display multicast group membership information for IPv4 and IPv6.
   --interfaces, -i
       Display a table of all network interfaces.
   --masquerade, -M
       Display a list of masqueraded connections.
   --statistics, -s
       Display summary statistics for each protocol.

OPTIONS         top

   --verbose, -v
       Tell the user what is going on by being verbose. Especially print
       some useful information about unconfigured address families.
   --wide, -W
       Do not truncate IP addresses by using output as wide as needed. This
       is optional for now to not break existing scripts.
   --numeric, -n
       Show numerical addresses instead of trying to determine symbolic
       host, port or user names.
   --numeric-hosts
       shows numerical host addresses but does not affect the resolution of
       port or user names.
   --numeric-ports
       shows numerical port numbers but does not affect the resolution of
       host or user names.
   --numeric-users
       shows numerical user IDs but does not affect the resolution of host
       or port names.
   --protocol=family, -A
       Specifies the address families (perhaps better described as low level
       protocols) for which connections are to be shown.  family is a comma
       (',') separated list of address family keywords like inet, inet6,
       unix, ipx, ax25, netrom, econet, ddp, and bluetooth.  This has the
       same effect as using the --inet|-4, --inet6|-6, --unix|-x, --ipx,
       --ax25, --netrom, --ddp, and --bluetooth options.
       The address family inet (Iv4) includes raw, udp, udplite and tcp
       protocol sockets.
       The address family bluetooth (Iv4) includes l2cap and rfcomm protocol
       sockets.
   -c, --continuous
       This will cause netstat to print the selected information every
       second continuously.
   -e, --extend
       Display additional information.  Use this option twice for maximum
       detail.
   -o, --timers
       Include information related to networking timers.
   -p, --program
       Show the PID and name of the program to which each socket belongs.
   -l, --listening
       Show only listening sockets.  (These are omitted by default.)
   -a, --all
       Show both listening and non-listening sockets.  With the --interfaces
       option, show interfaces that are not up
   -F
       Print routing information from the FIB.  (This is the default.)
   -C
       Print routing information from the route cache.

OUTPUT         top

   Active Internet connections (TCP, UDP, UDPLite, raw)
   Proto
       The protocol (tcp, udp, udpl, raw) used by the socket.
   Recv-Q
       Established: The count of bytes not copied by the user program
       connected to this socket.  Listening: Since Kernel 2.6.18 this column
       contains the current syn backlog.
   Send-Q
       Established: The count of bytes not acknowledged by the remote host.
       Listening: Since Kernel 2.6.18 this column contains the maximum size
       of the syn backlog.
   Local Address
       Address and port number of the local end of the socket.  Unless the
       --numeric (-n) option is specified, the socket address is resolved to
       its canonical host name (FQDN), and the port number is translated
       into the corresponding service name.
   Foreign Address
       Address and port number of the remote end of the socket.  Analogous
       to "Local Address".
   State
       The state of the socket. Since there are no states in raw mode and
       usually no states used in UDP and UDPLite, this column may be left
       blank. Normally this can be one of several values:
       ESTABLISHED
              The socket has an established connection.
       SYN_SENT
              The socket is actively attempting to establish a connection.
       SYN_RECV
              A connection request has been received from the network.
       FIN_WAIT1
              The socket is closed, and the connection is shutting down.
       FIN_WAIT2
              Connection is closed, and the socket is waiting for a shutdown
              from the remote end.
       TIME_WAIT
              The socket is waiting after close to handle packets still in
              the network.
       CLOSE  The socket is not being used.
       CLOSE_WAIT
              The remote end has shut down, waiting for the socket to close.
       LAST_ACK
              The remote end has shut down, and the socket is closed.
              Waiting for acknowledgement.
       LISTEN The socket is listening for incoming connections.  Such
              sockets are not included in the output unless you specify the
              --listening (-l) or --all (-a) option.
       CLOSING
              Both sockets are shut down but we still don't have all our
              data sent.
       UNKNOWN
              The state of the socket is unknown.
   User
       The username or the user id (UID) of the owner of the socket.
   PID/Program name
       Slash-separated pair of the process id (PID) and process name of the
       process that owns the socket.  --program causes this column to be
       included.  You will also need superuser privileges to see this
       information on sockets you don't own.  This identification
       information is not yet available for IPX sockets.
   Timer
       (this needs to be written)
   Active UNIX domain Sockets
   Proto
       The protocol (usually unix) used by the socket.
   RefCnt
       The reference count (i.e. attached processes via this socket).
   Flags
       The flags displayed is SO_ACCEPTON (displayed as ACC), SO_WAITDATA
       (W) or SO_NOSPACE (N).  SO_ACCECPTON is used on unconnected sockets
       if their corresponding processes are waiting for a connect request.
       The other flags are not of normal interest.
   Type
       There are several types of socket access:
       SOCK_DGRAM
              The socket is used in Datagram (connectionless) mode.
       SOCK_STREAM
              This is a stream (connection) socket.
       SOCK_RAW
              The socket is used as a raw socket.
       SOCK_RDM
              This one serves reliably-delivered messages.
       SOCK_SEQPACKET
              This is a sequential packet socket.
       SOCK_PACKET
              Raw interface access socket.
       UNKNOWN
              Who ever knows what the future will bring us - just fill in
              here :-)
   State
       This field will contain one of the following Keywords:
       FREE   The socket is not allocated
       LISTENING
              The socket is listening for a connection request.  Such
              sockets are only included in the output if you specify the
              --listening (-l) or --all (-a) option.
       CONNECTING
              The socket is about to establish a connection.
       CONNECTED
              The socket is connected.
       DISCONNECTING
              The socket is disconnecting.
       (empty)
              The socket is not connected to another one.
       UNKNOWN
              This state should never happen.
   PID/Program name
       Process ID (PID) and process name of the process that has the socket
       open.  More info available in Active Internet connections section
       written above.
   Path
       This is the path name as which the corresponding processes attached
       to the socket.
   Active IPX sockets
       (this needs to be done by somebody who knows it)
   Active NET/ROM sockets
       (this needs to be done by somebody who knows it)
   Active AX.25 sockets
       (this needs to be done by somebody who knows it)

FILES         top

       /etc/services -- The services translation file
       /proc -- Mount point for the proc filesystem, which gives access to
       kernel status information via the following files.
       /proc/net/dev -- device information
       /proc/net/raw -- raw socket information
       /proc/net/tcp -- TCP socket information
       /proc/net/udp -- UDP socket information
       /proc/net/udplite -- UDPLite socket information
       /proc/net/igmp -- IGMP multicast information
       /proc/net/unix -- Unix domain socket information
       /proc/net/ipx -- IPX socket information
       /proc/net/ax25 -- AX25 socket information
       /proc/net/appletalk -- DDP (appletalk) socket information
       /proc/net/nr -- NET/ROM socket information
       /proc/net/route -- IP routing information
       /proc/net/ax25_route -- AX25 routing information
       /proc/net/ipx_route -- IPX routing information
       /proc/net/nr_nodes -- NET/ROM nodelist
       /proc/net/nr_neigh -- NET/ROM neighbours
       /proc/net/ip_masquerade -- masqueraded connections
       /sys/kernel/debug/bluetooth/l2cap -- Bluetooth L2CAP information
       /sys/kernel/debug/bluetooth/rfcomm -- Bluetooth serial connections
       /proc/net/snmp -- statistics

SEE ALSO         top

       route(8), ifconfig(8), iptables(8), proc(5) ss(8) ip(8)

BUGS         top

       Occasionally strange information may appear if a socket changes as it
       is viewed. This is unlikely to occur.

AUTHORS         top

       The netstat user interface was written by Fred Baumgarten
       <dc6iq@insu1.etec.uni-karlsruhe.de>, the man page basically by Matt
       Welsh <mdw@tc.cornell.edu>. It was updated by Alan Cox
       <Alan.Cox@linux.org>, updated again by Tuan Hoang
       <tqhoang@bigfoot.com>. The man page and the command included in the
       net-tools package is totally rewritten by Bernd Eckenfels
       <ecki@linux.de>.  UDPLite options were added by Brian Micek
       <bmicek@gmail.com>

COLOPHON         top

       This page is part of the net-tools (networking utilities) project.
       Information about the project can be found at 
       ⟨http://net-tools.sourceforge.net/⟩.  If you have a bug report for
       this manual page, see ⟨http://net-tools.sourceforge.net/⟩.  This page
       was obtained from the project's upstream Git repository 
       ⟨git://git.code.sf.net/p/net-tools/code⟩ on 2017-07-05.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org
net-tools                        2014-10-07                       NETSTAT(8)

Pages that refer to this page: networks(5)proc(5)icmp(7)netcap(8)route(8)traceroute(8)