Linux Ascendency Trace Of Piece Of Occupation Tutorial For Beginners 37 - Netstat Command

NETSTAT(8)                 Linux Programmer's Manual                NETSTAT(8)    NAME        netstat  - Print network connections, routing tables, interface statis‐        tics, masquerade connections, too 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]] [--ver‐        bose|-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] [--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 almost the Linux networking subsystem.  The        type of information printed is controlled past times  the  get  argument,  as        follows:     (none)        By  default,  netstat  displays  a  listing of opened upward sockets.  If yous don't        specify whatever address families, too thence the active sockets of all configured        address families volition last printed.     --route , -r        Display  the inwardness routing tables. See the description inwards route(8) for        details.  netstat -r too road -e attain the same output.     --groups , -g        Display multicast grouping membership information for IPv4 too IPv6.     --interfaces, -i        Display a tabular array of all network interfaces.     --masquerade , -M        Display a listing of masqueraded connections.     --statistics , -s        Display summary statistics for each protocol.  OPTIONS    --verbose , -v        Tell the user what is going on past times existence verbose. Especially impress  some        useful information almost unconfigured address families.     --wide , -W        Do non truncate IP addresses past times using output every bit broad every bit needed. This is        optional for similar a shot to non interruption existing scripts.     --numeric , -n        Show numerical addresses instead of trying to create upward one's hear symbolic  host,        port or user names.     --numeric-hosts        shows  numerical  host  addresses but does non impact the resolution of        port or user names.     --numeric-ports        shows numerical port numbers but does non impact the resolution of host        or user names.     --numeric-users        shows  numerical user IDs but does non impact the resolution of host or        port names.      --protocol=family , -A        Specifies the address families (perhaps amend described every bit  depression  level        protocols)  for  which  connections are to last shown.  menage unit of measurement is a comma        (',') separated listing of address menage unit of measurement keywords similar inet,  unix,  ipx,        ax25,  netrom,  too ddp.  This has the same upshot every bit using the --inet,        --unix (-x), --ipx, --ax25, --netrom, too --ddp options.         The address menage unit of measurement inet includes raw, udp too tcp protocol sockets.     -c, --continuous        This volition campaign netstat to impress the selected information every  second        continuously.     -e, --extend        Display  additional  information.   Use  this  selection twice for maximum        detail.     -o, --timers        Include information related to networking timers.     -p, --program        Show the PID too mention of the programme to which each socket belongs.     -l, --listening        Show solely listening sockets.  (These are omitted past times default.)     -a, --all        Show both listening too non-listening sockets.  With  the  --interfaces        option, demo interfaces that are non up     -F        Print routing information from the FIB.  (This is the default.)     -C        Print routing information from the road cache.  OUTPUT    Active Internet connections (TCP, UDP, raw)    Proto        The protocol (tcp, udp, raw) used past times the socket.     Recv-Q        The  count  of  bytes  non copied past times the user programme connected to this        socket.     Send-Q        The count of bytes non acknowledged past times the remote host.     Local Address        Address too port discover of the local terminate of  the  socket.   Unless  the        --numeric  (-n)  selection is specified, the socket address is resolved to        its canonical host mention (FQDN), too the port discover is translated  into        the corresponding service name.     Foreign Address        Address  too port discover of the remote terminate of the socket.  Analogous to        "Local Address."     State        The terra firma of the socket. Since at that spot are no states inwards raw agency too usu‐        ally  no  states  used  inwards UDP, this column may last left blank. Normally        this tin last 1 of several values:         ESTABLISHED               The socket has an established connection.         SYN_SENT               The socket is actively attempting to flora a connection.         SYN_RECV               H5N1 connexion asking has been received from the network.         FIN_WAIT1               The socket is closed, too the connexion is shutting down.         FIN_WAIT2               Connection is closed, too the socket is waiting for  a  shutdown               from the remote end.         TIME_WAIT               The socket is waiting later roughly have packets withal inwards the               network.         CLOSE  The socket is non existence used.         CLOSE_WAIT               The remote terminate has unopen down, waiting for the socket to close.         LAST_ACK               The remote terminate has unopen down, too the socket is closed.  Waiting               for acknowledgement.         LISTEN The  socket is listening for incoming connections.  Such sockets               are non included inwards the output unless yous specify the  --listen‐               ing (-l) or --all (-a) option.         CLOSING               Both  sockets are unopen downwardly but nosotros withal don't accept all our data               sent.         UNKNOWN               The terra firma of the socket is unknown.     User        The username or the user id (UID) of the possessor of the socket.     PID/Program name        Slash-separated dyad of the procedure id (PID) too procedure  mention  of  the        procedure  that  owns  the  socket.   --program  causes this column to be        included.  You volition also involve superuser privileges to meet this informa‐        tion  on sockets yous don't own.  This identification information is not        yet available for IPX sockets.     Timer        (this needs to last written)     Active UNIX domain Sockets    Proto        The protocol (usually unix) used past times the socket.     RefCnt        The reference count (i.e. attached processes via this socket).     Flags        The flags displayed is SO_ACCEPTON (displayed every bit 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 non of normal interest.     Type        There are several types of socket access:         SOCK_DGRAM               The socket is used inwards Datagram (connectionless) mode.         SOCK_STREAM               This is a current (connection) socket.         SOCK_RAW               The socket is used every bit a raw socket.         SOCK_RDM               This 1 serves reliably-delivered messages.         SOCK_SEQPACKET               This is a sequential packet socket.         SOCK_PACKET               Raw interface access socket.         UNKNOWN               Who always knows what the futurity volition choose us - simply fill upward inwards here               :-)     State        This champaign volition incorporate 1 of the next Keywords:         FREE   The socket is non allocated         LISTENING               The socket is listening for a connexion request.  Such  sockets               are  solely  included inwards the output if yous specify the --listening               (-l) or --all (-a) option.         CONNECTING               The socket is almost to flora a connection.         CONNECTED               The socket is connected.         DISCONNECTING               The socket is disconnecting.         (empty)               The socket is non connected to some other one.         UNKNOWN               This terra firma should never happen.     PID/Program name        Process ID (PID) too procedure mention of the procedure that  has  the  socket        open.  More information available inwards Active Internet connections department writ‐        10 above.     Path        This is the path mention every bit which the corresponding processes attached  to        the socket.     Active IPX sockets        (this needs to last done past times soul who knows it)     Active NET/ROM sockets        (this needs to last done past times soul who knows it)     Active AX.25 sockets        (this needs to last done past times soul who knows it)  NOTES        Starting amongst Linux liberate 2.2 netstat -i does non demo interface sta‐        tistics for alias interfaces. To larn per alias interface  counters  you        involve to setup explicit rules using the ipchains(8) command.   FILES        /etc/services -- The services translation file         /proc  --  Mount  indicate  for the proc filesystem, which gives access to        inwardness condition information via the next 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 foreign information may look if a socket changes  every bit  it        is viewed. This is unlikely to occur.  AUTHORS        The   netstat   user   interface   was   written   past times  Fred  Baumgarten        <dc6iq@insu1.etec.uni-karlsruhe.de>, the human being  page  basically  past times  Matt        Welsh    <mdw@tc.cornell.edu>.    It    was   updated   past times   Alan   Cox        <Alan.Cox@linux.org> but could attain amongst a flake to a greater extent than work.  It was updated        in 1 lawsuit again past times Tuan Hoang <tqhoang@bigfoot.com>.        The  human being  page  too  the  command  included inwards the net-tools bundle is        totally rewritten past times Bernd Eckenfels <ecki@linux.de>.    net-tools                         2008-11-16                        NETSTAT(8)