man netstat获取到的linux官方文档

NETSTAT(8)                               Linux Programmer's Manual                              NETSTAT(8)



NAME
       netstat  - Print network connections, routing tables, interface statistics, masquerade connections （伪装链接）,
       and multicast memberships


SYNOPSIS
       netstat  [address_family_options]  [--tcp|-t]  [--udp|-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]

       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]  [--con‐
       tinuous|-c]

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

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

       netstat {--version|-V}

       netstat {--help|-h}

       address_family_options:

       [-4] [-6] [--protocol={inet,unix,ipx,ax25,netrom,ddp}[,...]]   [--unix|-x]  [--inet|--ip]  [--ax25]
       [--ipx] [--netrom] [--ddp]


DESCRIPTION
       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
   --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  connec‐
       tions  are  to  be  shown.   family is a comma (',') separated list of address family keywords like
       inet, unix, ipx, ax25, netrom, and ddp.  This has the same effect as using the --inet, --unix (-x),
       --ipx, --ax25, --netrom, and --ddp options.

       The address family inet includes raw, udp 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 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
   Active Internet connections (TCP, UDP, raw)
   Proto
       The protocol (tcp, udp, raw) used by the socket.

   Recv-Q
       The count of bytes not copied by the user program connected to this socket.

   Send-Q
       The count of bytes not acknowledged by the remote host.

   Local Address
       Address and port number of the local end of the socket.  Unless the --numeric (-n) option is speci‐
       fied,  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,
       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 out‐
              put 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 con‐
       nect 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)

NOTES
       Starting with Linux release 2.2 netstat -i does not show interface statistics for alias interfaces.
       To get per alias interface counters you need to setup explicit rules using the ipchains(8) command.


FILES
       /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/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), ipchains(8), iptables(8), proc(5)

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]> but could do with a bit more  work.   It  was  updated  again  by  Tuan  Hoang
       <[email protected]>.
       The man page and the command included in the net-tools package is totally rewritten by Bernd Ecken‐
       fels <[email protected]>.



net-tools                                       2008-11-16                                      NETSTAT(8)