Man Linux: Main Page and Category List


       sdpnetstat  -  Print  network  connections,  routing  tables, interface
       statistics, masquerade connections, and multicast memberships


       sdpnetstat [address_family_options]  [--tcp|-t]  [--udp|-u]  [--raw|-w]
       [--sdp|-S]   [--listening|-l]   [--all|-a]  [--numeric|-n]  [--numeric-
       hosts][--numeric-ports][--numeric-ports]                [--symbolic|-N]
       [--extend|-e[--extend|-e]]  [--timers|-o] [--program|-p] [--verbose|-v]

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

       sdpnetstat         {--interfaces|-i}         [iface]         [--all|-a]
       [--extend|-e[--extend|-e]] [--verbose|-v] [--program|-p] [--numeric|-n]
       [--numeric-hosts][--numeric-ports][--numeric-ports] [--continuous|-c]

       sdpnetstat  {--groups|-g}  [--numeric|-n]  [--numeric-hosts][--numeric-
       ports][--numeric-ports] [--continuous|-c]

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

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

       sdpnetstat {--version|-V}

       sdpnetstat {--help|-h}


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


       Sdpnetstat prints information about  the  Linux  networking  subsystem.
       The type of information printed is controlled by the first argument, as

       By default, sdpnetstat 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.

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

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

   --masquerade , -M
       Display a list of masqueraded connections.

   --statistics , -s
       Display summary statistics for each protocol.


   --verbose , -v
       Tell the user what is going on by being verbose. Especially print  some
       useful information about unconfigured address families.

   --numeric , -n
       Show  numerical addresses instead of trying to determine symbolic host,
       port or user names.

       shows numerical host addresses but does not affect  the  resolution  of
       port or user names.

       shows numerical port numbers but does not affect the resolution of host
       or user names.

       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, 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  sdpnetstat  to  print the selected information every
       second continuously.

   -e, --extend
       Display additional information.  Use  this  option  twice  for  maximum

   -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 marked

       Print routing information from the FIB.  (This is the default.)

       Print routing information from the route cache.  UP.


   Active Internet connections (TCP, UDP, raw)
       The protocol (tcp, udp, raw) used by the socket.

       The count of bytes not copied by the user  program  connected  to  this

       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 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."

       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:

              The socket has an established connection.

              The socket is actively attempting to establish a connection.

              A connection request has been received from the network.

              The socket is closed, and the connection is shutting down.

              Connection  is  closed, and the socket is waiting for a shutdown
              from the remote end.

              The socket is waiting after close to handle packets still in the

       CLOSED The socket is not being used.

              The remote end has shut down, waiting for the socket to close.

              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.

              Both sockets are shut down but we still don’t have all our  data

              The state of the socket is unknown.

       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.

       (this needs to be written)

   Active UNIX domain Sockets
       The protocol (usually unix) used by the socket.

       The reference count (i.e. attached processes via this socket).

       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.

       There are several types of socket access:

              The socket is used in Datagram (connectionless) mode.

              This is a stream (connection) socket.

              The socket is used as a raw socket.

              This one serves reliably-delivered messages.

              This is a sequential packet socket.

              Raw interface access socket.

              Who ever knows what the future will bring us - just fill in here

       This field will contain one of the following Keywords:

       FREE   The socket is not allocated

              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.

              The socket is about to establish a connection.

              The socket is connected.

              The socket is disconnecting.

              The socket is not connected to another one.

              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.

       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)


       Starting with Linux release 2.2 sdpnetstat -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.


       /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


       route(8), ifconfig(8), ipchains(8), iptables(8), proc(5)


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


       The  sdpnetstat  user  interface  was  written   by   Fred   Baumgarten
       <>  the  man  page  basically  by Matt
       Welsh   <>.   It   was   updated    by    Alan    Cox
       <> but could do with a bit more work.  It was updated
       again by Tuan Hoang <>.
       The man page and the command  included  in  the  net-tools  package  is
       totally rewritten by Bernd Eckenfels <>.