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.\" @(#)netstat.1 6.14 (Berkeley) 7/27/91 33.\" 34.Dd July 27, 1991 35.Dt NETSTAT 1 36.Os BSD 4.2 37.Sh NAME 38.Nm netstat 39.Nd show network status 40.Sh SYNOPSIS 41.Nm netstat 42.Op Fl Aan 43.Op Fl f Ar address_family 44.Op Ar system 45.Op Ar core 46.Nm netstat 47.Op Fl himnrs 48.Op Fl f Ar address_family 49.Op Fl M Ar core 50.Op Fl N Ar system 51.Nm netstat 52.Op Fl n 53.Op Fl I Op Ar interface 54.Op Fl M Ar core 55.Op Fl N Ar system 56.Op Fl w Ar wait 57.Nm netstat 58.Op Fl p Ar protocol 59.Op Fl M Ar core 60.Op Fl N Ar system 61.Sh DESCRIPTION 62The 63.Nm netstat 64command symbolically displays the contents of various network-related 65data structures. 66There are a number of output formats, 67depending on the options for the information presented. 68The first form of the command displays a list of active sockets for 69each protocol. 70The second form presents the contents of one of the other network 71data structures according to the option selected. 72Using the third form, with a 73.Ar wait 74interval specified, 75.Nm netstat 76will continuously display the information regarding packet 77traffic on the configured network interfaces. 78The fourth form displays statistics about the named protocol. 79.Pp 80The options have the following meaning: 81.Bl -tag -width flag 82.It Fl A 83With the default display, 84show the address of any protocol control blocks associated with sockets; used 85for debugging. 86.It Fl a 87With the default display, 88show the state of all sockets; normally sockets used by 89server processes are not shown. 90.It Fl d 91With either interface display (option 92.Fl i 93or an interval, as described below), 94show the number of dropped packets. 95.It Fl h 96Show the state of the 97.Tn IMP 98host table. 99.It Fl i 100Show the state of interfaces which have been auto-configured 101(interfaces statically configured into a system, but not 102located at boot time are not shown). 103.It Fl I Ar interface 104Show information only about this interface; 105used with an 106.Ar wait 107interval as described below. 108.It Fl M 109Extract values associated with the name list from the specified core 110instead of the default 111.Pa /dev/kmem . 112.It Fl m 113Show statistics recorded by the memory management routines 114(the network manages a private pool of memory buffers). 115.It Fl N 116Extract the name list from the specified system instead of the default 117.Pa /vmunix . 118.It Fl n 119Show network addresses as numbers (normally 120.Nm netstat 121interprets addresses and attempts to display them 122symbolically). 123This option may be used with any of the display formats. 124.It Fl p Ar protocol 125Show statistics about 126.Ar protocol , 127which is either a well-known name for a protocol or an alias for it. Some 128protocol names and aliases are listed in the file 129.Pa /etc/protocols . 130A null response typically means that there are no interesting numbers to 131report. 132The program will complain if 133.Ar protocol 134is unknown or if there is no statistics routine for it. 135.It Fl s 136Show per-protocol statistics. 137.It Fl r 138Show the routing tables. 139When 140.Fl s 141is also present, show routing statistics instead. 142.It Fl f Ar address_family 143Limit statistics or address control block reports to those 144of the specified 145.Ar address family . 146The following address families 147are recognized: 148.Ar inet , 149for 150.Dv AF_INET , 151.Ar ns , 152for 153.Dv AF_NS , 154and 155.Ar unix , 156for 157.Dv AF_UNIX . 158.El 159.Pp 160The default display, for active sockets, shows the local 161and remote addresses, send and receive queue sizes (in bytes), protocol, 162and the internal state of the protocol. 163Address formats are of the form ``host.port'' or ``network.port'' 164if a socket's address specifies a network but no specific host address. 165When known the host and network addresses are displayed symbolically 166according to the data bases 167.Pa /etc/hosts 168and 169.Pa /etc/networks , 170respectively. If a symbolic name for an address is unknown, or if 171the 172.Fl n 173option is specified, the address is printed numerically, according 174to the address family. 175For more information regarding 176the Internet ``dot format,'' 177refer to 178.Xr inet 3 ) . 179Unspecified, 180or ``wildcard'', addresses and ports appear as ``*''. 181.Pp 182The interface display provides a table of cumulative 183statistics regarding packets transferred, errors, and collisions. 184The network addresses of the interface 185and the maximum transmission unit (``mtu'') are also displayed. 186.Pp 187The routing table display indicates the available routes and 188their status. Each route consists of a destination host or network 189and a gateway to use in forwarding packets. The flags field shows 190the state of the route (``U'' if ``up''), whether the route 191is to a gateway (``G''), whether the route was created dynamically 192by a redirect (``D''), and whether the route has been modified 193by a redirect (``M''). Direct routes are created for each 194interface attached to the local host; 195the gateway field for such entries shows the address of the outgoing interface. 196The refcnt field gives the 197current number of active uses of the route. Connection oriented 198protocols normally hold on to a single route for the duration of 199a connection while connectionless protocols obtain a route while sending 200to the same destination. 201The use field provides a count of the number of packets 202sent using that route. The interface entry indicates the network 203interface utilized for the route. 204.Pp 205When 206.Nm netstat 207is invoked with a 208.Ar wait 209interval argument, it displays a running count of statistics related to 210network interfaces. 211This display consists of a column for the primary interface (the first 212interface found during autoconfiguration) and a column summarizing 213information for all interfaces. 214The primary interface may be replaced with another interface with the 215.Fl I 216option. 217The first line of each screen of information contains a summary since the 218system was last rebooted. Subsequent lines of output show values 219accumulated over the preceding interval. 220.Sh SEE ALSO 221.Xr iostat 1 , 222.Xr nfsstat 1 , 223.Xr ps 1 , 224.Xr vmstat 1 , 225.Xr hosts 5 , 226.Xr networks 5 , 227.Xr protocols 5 , 228.Xr services 5 , 229.Xr trpt 8 , 230.Xr trsp 8 231.Sh HISTORY 232The 233.Nm netstat 234command appeared in 235.Bx 4.2 . 236.\" .Sh FILES 237.\" .Bl -tag -width /dev/kmem -compact 238.\" .It Pa /vmunix 239.\" default kernel namelist 240.\" .It Pa /dev/kmem 241.\" default memory file 242.\" .El 243.Sh BUGS 244The notion of errors is ill-defined. 245.Pp 246Collisions mean something else for the 247.Tn IMP . 248