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netstat의 state별 설명

by 버들도령 2019. 6. 16.
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LISTEN : 서버의 데몬이 떠서 접속 요청을 기다리는 상태

SYS-SENT : 로컬의 클라이언트 애플리케이션이 원격 호스트에 연결을 요청한 상태

SYS-RECEIVED : 서버가 클라이언트로 부터 접속 요구를 받아 클라이언트에게 응답을 했지만 아직 클라이언트에게 확인 메세지는 받지 않은 상태

ESTALISHED : 3-way-Handshaking 이 완료된후 서로 연결된 상태

FIN-WAIT, CLOSE-WAIT, FIN-WAIT2 : 서버에서 연결을 종료하기 위해 클라이언트에게 종결을 요청하고 회신을 받아 종료하는 과정의 상태

CLOSING : 흔하지 않지만 주로 확인 메세지가 존송 도중 분실된 상태

TIME-WAIT : 연결은 종료 되었지만 분실되었을지 모를 느린 세그먼트를 위해 당분간 소켓을 열어 놓은 상태

CLOSED : 완전히 종료

 

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Maintenance Commands                                  netstat(1M)

NAME
     netstat - show network status

SYNOPSIS
     netstat [-anv] [-f address_family] [-P protocol]

     netstat -g [-nv] [-f address_family]

     netstat -p [-n] [-f address_family]

     netstat  -s  [-f address_family]   [-P protocol]   [interval
     [count]]

     netstat -m [-v] [interval  [count]]

     netstat -i [-I interface] [-an] [-f address_family]  [inter-
     val [count]]

     netstat -r [-anv] [-f address_family | filter]

     netstat -M [-ns] [-f address_family]

     netstat -D [-I interface] [-f address_family]

     The  netstat  command  displays  the  contents  of   certain
     network-related  data structures in various formats, depend-
     ing on the options you select.

     The netstat command has the several forms shown in the  sec-
     tion, above, listed as follows:

       o  The first form of the command (with no  required  argu-
          ments)  displays a list of active sockets for each pro-
          tocol.

       o  The second, third, and fourth forms  (-g,  -p,  and  -s
          options)  display information from various network data
          structures.

       o  The fifth form  (-m  option)  displays  STREAMS  memory
          statistics.

       o  The sixth form (-i  option)  shows  the  state  of  the
          interfaces.

       o  The seventh  form  (-r  option)  displays  the  routing
          table.

       o  The eighth form  (-M  option)  displays  the  multicast
          routing table.

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Maintenance Commands                                  netstat(1M)

       o  The ninth form (-D option) displays the state  of  DHCP
          on one or all interfaces.

     These forms are described in greater detail below.

     With no arguments (the first form),  netstat  displays  con-
     nected  sockets  for  PF_INET, PF_INET6, and PF_UNIX, unless
     modified otherwise by the -f option.

     -a                      Show the state of all  sockets,  all
                             routing table entries, or all inter-
                             faces, both  physical  and  logical.
                             Normally,  listener  sockets used by
                             server  processes  are  not   shown.
                             Under  most  conditions, only inter-
                             face,  host,  network,  and  default
                             routes are shown and only the status
                             of physical interfaces is shown.

     -f address_family       Limit all displays to those  of  the
                             specified  address_family. The value
                             of address_family can be one of  the
                             following:

                             inet     For  the  AF_INET   address
                                      family  showing IPv4 infor-
                                      mation.

                             inet6    For  the  AF_INET6  address
                                      family  showing IPv6 infor-
                                      mation.

                             unix     For  the  AF_UNIX   address
                                      family.

     -f filter               With -r only, limit the  display  of
                             routes  to those matching the speci-
                             fied filter. A filter rule  consists
                             of a "keyword:value" pair. The known
                             keywords and the value syntax are:

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Maintenance Commands                                  netstat(1M)

                             af:{inet|inet6|unix|number}

                                 Selects an address family.  This
                                 is      identical      to     -f
                                 address_family and both syntaxes
                                 are supported.

                             {inif|outif}:{name|ifIndex|any|none}

                                 Selects  an  input   or   output
                                 interface.  You  can specify the
                                 interface by name (such as hme0)
                                 or  by ifIndex number (for exam-
                                 ple, 2). If  any  is  used,  the
                                 filter matches all routes having
                                 a specified interface  (anything
                                 other  than  null).  If  none is
                                 used,  the  filter  matches  all
                                 routes  having a null interface.
                                 Note that you can view the index
                                 number  (ifIndex)  for an inter-
                                 face  with  the  -a  option   of
                                 ifconfig(1M).

                             {src|dst}:{ip-
                             address[/mask]|any|none}

                                 Selects a source or  destination
                                 IP  address. If specified with a
                                 mask  length,  then  any  routes
                                 with  matching  or  longer (more
                                 specific) masks are selected. If
                                 any   is   used,  then  all  but
                                 addresses but 0 are selected. If
                                 none  is used, then address 0 is
                                 selected.

                             flags:[+ -]?[ABDGHLMSU]+

                                 Selects routes tagged  with  the
                                 specified flags. By default, the
                                 flags as specified must  be  set
                                 in  order to match. With a lead-
                                 ing +, the flags specified  must
                                 be  set  but others are ignored.

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Maintenance Commands                                  netstat(1M)

                                 With  a  leading  -,  the  flags
                                 specified  must  not  be set and
                                 others are permitted.

                             You can specify  multiple  instances
                             of  -f  to specify multiple filters.
                             For example:

                             % netstat -nr -f outif:hme0 -f outif:hme1 -f dst:10
.0.0.0/8

                             The   preceding   command   displays
                             routes  within  network  10.0.0.0/8,
                             with mask length 8 or  greater,  and
                             an  output  interface of either hme0
                             or  hme1,  and  excludes  all  other
                             routes.

     -g                      Show the multicast group memberships
                             for all interfaces. If the -v option
                             is included, source-specific member-
                             ship  information is also displayed.
                             See DISPLAYS, below.

     -i                      Show the  state  of  the  interfaces
                             that  are  used for IP traffic. Nor-
                             mally this shows statistics for  the
                             physical  interfaces.  When combined
                             with the -a option, this  will  also
                             report  information  for the logical
                             interfaces. See ifconfig(1M).

     -m                      Show the STREAMS memory statistics.

     -n                      Show network addresses  as  numbers.
                             netstat  normally displays addresses
                             as symbols. This option may be  used
                             with any of the display formats.

     -p                      Show the net to  media  tables.  See
                             DISPLAYS, below.

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Maintenance Commands                                  netstat(1M)

     -r                      Show the routing  tables.  Normally,
                             only  interface,  host, network, and
                             default routes are shown,  but  when
                             this  option is combined with the -a
                             option,   all   routes    will    be
                             displayed, including cache.

     -s                      Show per-protocol  statistics.  When
                             used with the -M option, show multi-
                             cast  routing  statistics   instead.
                             When  used  with the -a option, per-
                             interface   statistics    will    be
                             displayed,  when available, in addi-
                             tion to  statistics  global  to  the
                             system. See DISPLAYS, below.

     -v                      Verbose. Show additional information
                             for   the  sockets,  STREAMS  memory
                             statistics, routing table, and  mul-
                             ticast group memberships.

     -I interface            Show  the  state  of  a   particular
                             interface.   interface  can  be  any
                             valid  interface  such  as  hme0  or
                             eri0.   Normally,   the  status  and
                             statistics for  physical  interfaces
                             are  displayed.  When this option is
                             combined with the -a option,  infor-
                             mation for the logical interfaces is
                             also reported.

     -M                      Show the multicast  routing  tables.
                             When  used  with the -s option, show
                             multicast     routing     statistics
                             instead.

     -P protocol             Limit display of statistics or state
                             of  all  sockets to those applicable
                             to protocol. The protocol can be one
                             of  ip,  ipv6,  icmp,  icmpv6, icmp,
                             icmpv6, igmp, udp, tcp, rawip. rawip
                             can  also  be  specified as raw. The

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Maintenance Commands                                  netstat(1M)

                             command  accepts  protocol   options
                             only as all lowercase.

     -D                      Show the status of  DHCP  configured
                             interfaces.

     interval        Display statistics  accumulated  since  last
                     display  every  interval  seconds, repeating
                     forever, unless  count  is  specified.  When
                     invoked  with  interval,  the  first  row of
                     netstat output shows statistics  accumulated
                     since last reboot.

                     The following options support interval:  -i,
                     -m,  -s  and -Ms. Some values are configura-
                     tion parameters and are just redisplayed  at
                     each interval.

     count           Display interface statistics the  number  of
                     times  specified  by  count, at the interval
                     specified by interval.

DISPLAYS
  Active Sockets (First Form)
     The display for each  active  socket  shows  the  local  and
     remote address, the send and receive queue sizes (in bytes),
     the send and receive windows (in bytes),  and  the  internal
     state of the protocol.

     The  symbolic  format  normally  used  to   display   socket
     addresses is either:

     hostname.port
     when the name of the host is specified, or

     network.port
     if a socket address specifies  a  network  but  no  specific
     host.

     The numeric host address or network number  associated  with
     the  socket  is  used  to look up the corresponding symbolic
     hostname or network name in the hosts or networks database.

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Maintenance Commands                                  netstat(1M)

     If the network or hostname for an address is not  known,  or
     if the -n option is specified, the numerical network address
     is shown. Unspecified, or "wildcard",  addresses  and  ports
     appear  as  "*". For more information regarding the Internet
     naming conventions, refer to inet(7P) and inet6(7P).

     For SCTP sockets, because an endpoint can be represented  by
     multiple  addresses,  the  verbose  option (-v) displays the
     list of all the local and remote addresses.

  TCP Sockets
     The possible state values for TCP sockets are as follows:

     BOUND

         Bound, ready to connect or listen.

     CLOSED

         Closed. The socket is not being used.

     CLOSING

         Closed, then remote shutdown; awaiting acknowledgment.

     CLOSE_WAIT

         Remote shutdown; waiting for the socket to close.

     ESTABLISHED

         Connection has been established.

     FIN_WAIT_1

         Socket closed; shutting down connection.

     FIN_WAIT_2

         Socket closed; waiting for shutdown from remote.

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Maintenance Commands                                  netstat(1M)

     IDLE

         Idle, opened but not bound.

     LAST_ACK

         Remote shutdown, then closed; awaiting acknowledgment.

     LISTEN

         Listening for incoming connections.

     SYN_RECEIVED

         Initial synchronization of the connection under way.

     SYN_SENT

         Actively trying to establish connection.

     TIME_WAIT

         Wait after close for remote shutdown retransmission.

  SCTP Sockets
     The possible state values for SCTP sockets are as follows:

     CLOSED

         Closed. The socket is not being used.

     LISTEN

         Listening for incoming associations.

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Maintenance Commands                                  netstat(1M)

     ESTABLISHED

         Association has been established.

     COOKIE_WAIT

         INIT has been sent to the peer, awaiting acknowledgment.

     COOKIE_ECHOED

         State cookie from the INIT-ACK  has  been  sent  to  the
         peer, awaiting acknowledgement.

     SHUTDOWN_PENDING

         SHUTDOWN has been received from the upper layer,  await-
         ing  acknowledgement  of  all  outstanding DATA from the
         peer.

     SHUTDOWN_SENT

         All  outstanding  data  has  been  acknowledged  in  the
         SHUTDOWN_SENT state. SHUTDOWN has been sent to the peer,
         awaiting acknowledgement.

     SHUTDOWN_RECEIVED

         SHUTDOWN has been received from the peer, awaiting  ack-
         nowledgement of all outstanding DATA.

     SHUTDOWN_ACK_SENT

         All  outstanding  data  has  been  acknowledged  in  the
         SHUTDOWN_RECEIVED  state.  SHUTDOWN_ACK has been sent to
         the peer.

  Network Data Structures (Second Through Fifth Forms)

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Maintenance Commands                                  netstat(1M)

     The form of the display depends upon which of  the  -g,  -m,
     -p, or -s options you select.

     -g       Displays the list of multicast group membership.

     -m       Displays the memory  usage,  for  example,  STREAMS
              mblks.

     -p       Displays the net to media mapping table. For  IPv4,
              the  address  resolution  table  is  displayed. See
              arp(1M). For IPv6, the neighbor cache is displayed.

     -s       Displays the statistics for  the  various  protocol
              layers.

     The statistics use the MIB specified variables. The  defined
     values for ipForwarding are:

     forwarding(1)           Acting as a gateway.

     not-forwarding(2)       Not acting as a gateway.

     The IPv6 and ICMPv6 protocol layers  maintain  per-interface
     statistics.  If  the  -a  option  is  specified  with the -s
     option, then the per-interface statistics  as  well  as  the
     total  sums  are  displayed.  Otherwise, just the sum of the
     statistics are shown.

     For the second, third, and fourth forms of the command,  you
     must  specify  at  least  -g, -p, or -s. You can specify any
     combination of these options. You can also specify  -m  (the
     fifth  form)  with any set of the -g, -p, and -s options. If
     you specify more than one of these options, netstat displays
     the information for each one of them.

  Interface Status (Sixth Form)
     The interface  status  display  lists  information  for  all
     current  interfaces, one interface per line. If an interface
     is specified using the -I option,  it  displays  information

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Maintenance Commands                                  netstat(1M)

     for only the specified interface.

     The list  consists  of  the  interface  name,  mtu  (maximum
     transmission    unit,    or    maximum    packet   size)(see
     ifconfig(1M)),  the  network  to  which  the  interface   is
     attached,  addresses for each interface, and counter associ-
     ated with the interface. The counters  show  the  number  of
     input  packets, input errors, output packets, output errors,
     and collisions, respectively. For Point-to-Point interfaces,
     the  Net/Dest field is the name or address on the other side
     of the link.

     If the -a option is specified with either the -i  option  or
     the  -I option, then the output includes names of the physi-
     cal interface(s), counts for input packets and output  pack-
     ets for each logical interface, plus additional information.

     If the -n option is specified,  the  list  displays  the  IP
     address instead of the interface name.

     If an optional interval is specified,  the  output  will  be
     continually  displayed in interval seconds until interrupted
     by the user or until count is reached. See .

     The physical interface is specified  using  the  -I  option.
     When  used  with  the  interval  operand,  output for the -I
     option has the following format:

     input    eri0          output        input          (Total)    output
     packets  errs  packets errs  colls   packets  errs  packets   errs   colls
     227681   0     659471  1     502     261331   0     99597     1      502
     10       0     0       0     0       10       0     0         0      0
     8        0     0       0     0       8        0     0         0      0
     10       0     2       0     0       10       0     2         0      0

     If the input interface is not specified, the first interface
     of address family inet or inet6 will be displayed.

  Routing Table (Seventh Form)
     The routing table display lists the available routes and the
     status of each. Each route consists of a destination host or
     network, and a gateway to use  in  forwarding  packets.  The
     flags  column shows the status of the route. These flags are
     as follows:

     U

         Indicates route is "up".

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Maintenance Commands                                  netstat(1M)

     G

         Route is to a gateway.

     H

         Route is to a host and not a network.

     M

         Redundant route established with the -multirt option.

     S

         Route was established using the -setsrc option.

     D

         Route was created dynamically by a redirect.

     If the -a option is specified, there will be routing entries
     with the following flags:

     A

         Combined routing and address resolution entries.

     B

         Broadcast addresses.

     L

         Local addresses for the host.

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Maintenance Commands                                  netstat(1M)

     Interface routes are created for each interface attached  to
     the local host; the gateway field for such entries shows the
     address of the outgoing interface.

     The use column displays the number of packets sent  using  a
     combined  routing  and address resolution (A) or a broadcast
     (B) route. For a local (L) route, this count is  the  number
     of  packets  received,  and  for  all other routes it is the
     number of times the routing entry has been used to create  a
     new combined route and address resolution entry.

     The interface entry indicates the network interface utilized
     for the route.

  Multicast Routing Tables (Eighth Form)
     The multicast routing table consists of the  virtual  inter-
     face table and the actual routing table.

  DHCP Interface Information (Ninth Form)
     The DHCP interface information  consists  of  the  interface
     name,  its  current state, lease information, packet counts,
     and a list of flags.

     The states correlate with the specifications  set  forth  in
     RFC 2131.

     Lease information includes:

       o  when the lease began;

       o  when lease renewal will begin; and

       o  when the lease will expire.

     The flags currently defined include:

     BOOTP                   The interface has a  lease  obtained
                             through BOOTP.

     BUSY                    The interface is busy  with  a  DHCP
                             transaction.

     PRIMARY                 The interface is the primary  inter-
                             face. See dhcpinfo(1).

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Maintenance Commands                                  netstat(1M)

     FAILED                  The interface is  in  failure  state
                             and must be manually restarted.

     Packet counts are maintained for the number of packets sent,
     the  number  of  packets  received,  and the number of lease
     offers declined by the DHCP client. All three  counters  are
     initialized  to  zero and then incremented while obtaining a
     lease. The counters are  reset  when  the  period  of  lease
     renewal   begins  for  the  interface.  Thus,  the  counters
     represent either the number of packets sent,  received,  and
     declined while obtaining the current lease, or the number of
     packets sent, received, and  declined  while  attempting  to
     obtain a future lease.

     /etc/default/inet_type          DEFAULT_IP setting

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|

     arp(1M),    dhcpinfo(1),    dhcpagent(1M),     ifconfig(1M),
     iostat(1M),     kstat(1M),     mibiisa(1M),    savecore(1M),
     vmstat(1M),  hosts(4),  inet_type(4),  networks(4),   proto-
     cols(4),  services(4),  attributes(5),  kstat(7D), inet(7P),
     inet6(7P)

     Droms, R., RFC 2131, Dynamic  Host  Configuration  Protocol,
     Network Working Group, March 1997.

     When displaying interface information,  netstat  honors  the
     DEFAULT_IP  setting  in /etc/default/inet_type. If it is set
     to IP_VERSION4, then netstat will omit information  relating
     to  IPv6 interfaces, statistics, connections, routes and the
     like.

     However,  you  can  override  the  DEFAULT_IP   setting   in
     /etc/default/inet_type  on the command-line. For example, if
     you have used the command-line to  explicitly  request  IPv6

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Maintenance Commands                                  netstat(1M)

     information  by using the inet6 address family or one of the
     IPv6 protocols, it will override the DEFAULT_IP setting.

     If you need to examine network status information  following
     a  kernel  crash, use the mdb(1) utility on the savecore(1M)
     output.

     The netstat utility obtains TCP statistics from  the  system
     by  opening  /dev/tcp  and issuing queries. Because of this,
     netstat might display an extra, unused  connection  in  IDLE
     state when reporting connection status.

     Previous versions of netstat had  undocumented  methods  for
     reporting  kernel  statistics  published using the kstat(7D)
     facility. This functionality has been removed. Use kstat(1M)
     instead.

SunOS 5.10           Last change: 4 Mar 2005                   15

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