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



NAME
       netstat  - Print network connections, routing tables, interface statistics, masquerade connections, and multi‐
       cast memberships


SYNOPSIS
       netstat [address_family_options] [--tcp|-t] [--udp|-u] [--udplite|-U] [--raw|-w]  [--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] [delay]

       netstat  {--route|-r}  [address_family_options]   [--extend|-e[--extend|-e]]   [--verbose|-v]   [--numeric|-n]
       [--numeric-hosts] [--numeric-ports] [--numeric-users] [--continuous|-c] [delay]

       netstat {--interfaces|-I|-i} [--all|-a] [--extend|-e] [--verbose|-v] [--program|-p] [--numeric|-n] [--numeric-
       hosts] [--numeric-ports] [--numeric-users] [--continuous|-c] [delay]

       netstat {--groups|-g} [--numeric|-n] [--numeric-hosts] [--numeric-ports]  [--numeric-users]  [--continuous|-c]
       [delay]

       netstat  {--masquerade|-M}  [--extend|-e] [--numeric|-n] [--numeric-hosts] [--numeric-ports] [--numeric-users]
       [--continuous|-c] [delay]

       netstat {--statistics|-s} [--tcp|-t] [--udp|-u] [--udplite|-U] [--raw|-w] [delay]

       netstat {--version|-V}

       netstat {--help|-h}

       address_family_options:

       [-4|--inet]   [-6|--inet6]   [--protocol={inet,inet6,unix,ipx,ax25,netrom,ddp,    ...    }    ]    [--unix|-x]
       [--inet|--ip|--tcpip] [--ax25] [--x25] [--rose] [--ash] [--ipx] [--netrom] [--ddp|--appletalk] [--econet|--ec]


NOTES
       This  program  is obsolete.  Replacement for netstat is ss.  Replacement for netstat -r is ip route.  Replace‐
       ment for netstat -i is ip -s link.  Replacement for netstat -g is ip maddr.


DESCRIPTION
       Netstat prints information about the Linux networking subsystem.  The type  of  information  printed  is  con‐
       trolled 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  pro‐
       duce the same output.

   --groups , -g
       Display multicast group membership information for IPv4 and IPv6.

   --interfaces=iface , -I=iface , -i
       Display a table of all network interfaces, or the specified iface.

   --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, and ddp.  This has the same effect as using the --inet|-4, --inet6|-6, --unix|-x, --ipx,
       --ax25, --netrom, and --ddp options.

       The address family inet (Iv4) includes raw, udp, udplite and tcp 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 (for TCP this means established connections) sockets.  With the --inter‐
       faces 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.

   delay
       Netstat will cycle printing through statistics every delay seconds.

OUTPUT

   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  cor‐
       responding 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.
       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
       (this needs to be done by somebody who knows it)

FILES
       /etc/services -- The services translation file

       /proc  -- Mount point for the proc filesystem, which gives access to kernel status information via the follow‐
       ing 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

       /proc/net/snmp -- statistics

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

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

AUTHORS
       The netstat user interface was written by Fred Baumgarten <[email protected]>,  the  man  page
       basically  by  Matt Welsh <[email protected]>. It was updated by Alan Cox <[email protected]>, updated again
       by Tuan Hoang <[email protected]>. The man page and the command included in the net-tools package is totally