1.\" Copyright (c) 1983, 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)netstat.1 6.14 (Berkeley) 7/27/91 33.\" $Id: netstat.1,v 1.2 1993/08/01 07:30:27 mycroft Exp $ 34.\" 35.Dd July 27, 1991 36.Dt NETSTAT 1 37.Os BSD 4.2 38.Sh NAME 39.Nm netstat 40.Nd show network status 41.Sh SYNOPSIS 42.Nm netstat 43.Op Fl Aan 44.Op Fl f Ar address_family 45.Op Ar system 46.Op Ar core 47.Nm netstat 48.Op Fl himnrs 49.Op Fl f Ar address_family 50.Op Fl M Ar core 51.Op Fl N Ar system 52.Nm netstat 53.Op Fl n 54.Op Fl I Op Ar interface 55.Op Fl M Ar core 56.Op Fl N Ar system 57.Op Fl w Ar wait 58.Nm netstat 59.Op Fl p Ar protocol 60.Op Fl M Ar core 61.Op Fl N Ar system 62.Sh DESCRIPTION 63The 64.Nm netstat 65command symbolically displays the contents of various network-related 66data structures. 67There are a number of output formats, 68depending on the options for the information presented. 69The first form of the command displays a list of active sockets for 70each protocol. 71The second form presents the contents of one of the other network 72data structures according to the option selected. 73Using the third form, with a 74.Ar wait 75interval specified, 76.Nm netstat 77will continuously display the information regarding packet 78traffic on the configured network interfaces. 79The fourth form displays statistics about the named protocol. 80.Pp 81The options have the following meaning: 82.Bl -tag -width flag 83.It Fl A 84With the default display, 85show the address of any protocol control blocks associated with sockets; used 86for debugging. 87.It Fl a 88With the default display, 89show the state of all sockets; normally sockets used by 90server processes are not shown. 91.It Fl d 92With either interface display (option 93.Fl i 94or an interval, as described below), 95show the number of dropped packets. 96.It Fl h 97Show the state of the 98.Tn IMP 99host table. 100.It Fl i 101Show the state of interfaces which have been auto-configured 102(interfaces statically configured into a system, but not 103located at boot time are not shown). 104.It Fl I Ar interface 105Show information only about this interface; 106used with an 107.Ar wait 108interval as described below. 109.It Fl M 110Extract values associated with the name list from the specified core 111instead of the default 112.Pa /dev/kmem . 113.It Fl m 114Show statistics recorded by the memory management routines 115(the network manages a private pool of memory buffers). 116.It Fl N 117Extract the name list from the specified system instead of the default 118.Pa /vmunix . 119.It Fl n 120Show network addresses as numbers (normally 121.Nm netstat 122interprets addresses and attempts to display them 123symbolically). 124This option may be used with any of the display formats. 125.It Fl p Ar protocol 126Show statistics about 127.Ar protocol , 128which is either a well-known name for a protocol or an alias for it. Some 129protocol names and aliases are listed in the file 130.Pa /etc/protocols . 131A null response typically means that there are no interesting numbers to 132report. 133The program will complain if 134.Ar protocol 135is unknown or if there is no statistics routine for it. 136.It Fl s 137Show per-protocol statistics. 138.It Fl r 139Show the routing tables. 140When 141.Fl s 142is also present, show routing statistics instead. 143.It Fl f Ar address_family 144Limit statistics or address control block reports to those 145of the specified 146.Ar address family . 147The following address families 148are recognized: 149.Ar inet , 150for 151.Dv AF_INET , 152.Ar ns , 153for 154.Dv AF_NS , 155and 156.Ar unix , 157for 158.Dv AF_UNIX . 159.El 160.Pp 161The default display, for active sockets, shows the local 162and remote addresses, send and receive queue sizes (in bytes), protocol, 163and the internal state of the protocol. 164Address formats are of the form ``host.port'' or ``network.port'' 165if a socket's address specifies a network but no specific host address. 166When known the host and network addresses are displayed symbolically 167according to the data bases 168.Pa /etc/hosts 169and 170.Pa /etc/networks , 171respectively. If a symbolic name for an address is unknown, or if 172the 173.Fl n 174option is specified, the address is printed numerically, according 175to the address family. 176For more information regarding 177the Internet ``dot format,'' 178refer to 179.Xr inet 3 ) . 180Unspecified, 181or ``wildcard'', addresses and ports appear as ``*''. 182.Pp 183The interface display provides a table of cumulative 184statistics regarding packets transferred, errors, and collisions. 185The network addresses of the interface 186and the maximum transmission unit (``mtu'') are also displayed. 187.Pp 188The routing table display indicates the available routes and 189their status. Each route consists of a destination host or network 190and a gateway to use in forwarding packets. The flags field shows 191the state of the route (``U'' if ``up''), whether the route 192is to a gateway (``G''), whether the route was created dynamically 193by a redirect (``D''), and whether the route has been modified 194by a redirect (``M''). Direct routes are created for each 195interface attached to the local host; 196the gateway field for such entries shows the address of the outgoing interface. 197The refcnt field gives the 198current number of active uses of the route. Connection oriented 199protocols normally hold on to a single route for the duration of 200a connection while connectionless protocols obtain a route while sending 201to the same destination. 202The use field provides a count of the number of packets 203sent using that route. The interface entry indicates the network 204interface utilized for the route. 205.Pp 206When 207.Nm netstat 208is invoked with a 209.Ar wait 210interval argument, it displays a running count of statistics related to 211network interfaces. 212This display consists of a column for the primary interface (the first 213interface found during autoconfiguration) and a column summarizing 214information for all interfaces. 215The primary interface may be replaced with another interface with the 216.Fl I 217option. 218The first line of each screen of information contains a summary since the 219system was last rebooted. Subsequent lines of output show values 220accumulated over the preceding interval. 221.Sh SEE ALSO 222.Xr iostat 1 , 223.Xr nfsstat 1 , 224.Xr ps 1 , 225.Xr vmstat 1 , 226.Xr hosts 5 , 227.Xr networks 5 , 228.Xr protocols 5 , 229.Xr services 5 , 230.Xr trpt 8 , 231.Xr trsp 8 232.Sh HISTORY 233The 234.Nm netstat 235command appeared in 236.Bx 4.2 . 237.\" .Sh FILES 238.\" .Bl -tag -width /dev/kmem -compact 239.\" .It Pa /vmunix 240.\" default kernel namelist 241.\" .It Pa /dev/kmem 242.\" default memory file 243.\" .El 244.Sh BUGS 245The notion of errors is ill-defined. 246.Pp 247Collisions mean something else for the 248.Tn IMP . 249