1.\" Copyright (c) 1983, 1990, 1992, 1993 2.\" The Regents of the University of California. 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 8.8 (Berkeley) 4/18/94 33.\" 34.Dd April 18, 1994 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 Fl M Ar core 45.Op Fl N Ar system 46.Nm netstat 47.Op Fl dghimnrs 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 dn 53.Op Fl I 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 f Ar address_family 96Limit statistics or address control block reports to those 97of the specified 98.Ar address family . 99The following address families 100are recognized: 101.Ar inet , 102for 103.Dv AF_INET , 104.Ar ns , 105for 106.Dv AF_NS , 107.Ar iso , 108for 109.Dv AF_ISO , 110and 111.Ar unix , 112for 113.Dv AF_UNIX . 114.It Fl g 115Show information related to multicast (group address) routing. 116By default, show the IP Multicast virtual-interface and routing tables. 117If the 118.Fl s 119option is also present, show multicast routing statistics. 120.It Fl h 121Show the state of the 122.Tn IMP 123host table (obsolete). 124.It Fl I Ar interface 125Show information about the specified interface; 126used with a 127.Ar wait 128interval as described below. 129.It Fl i 130Show the state of interfaces which have been auto-configured 131(interfaces statically configured into a system, but not 132located at boot time are not shown). 133If the 134.Fl a 135options is also present, multicast addresses currently in use are shown 136for each Ethernet interface and for each IP interface address. 137Multicast addresses are shown on separate lines following the interface 138address with which they are associated. 139.It Fl M 140Extract values associated with the name list from the specified core 141instead of the default 142.Pa /dev/kmem . 143.It Fl m 144Show statistics recorded by the memory management routines 145(the network manages a private pool of memory buffers). 146.It Fl N 147Extract the name list from the specified system instead of the default 148.Pa /kernel . 149.It Fl n 150Show network addresses as numbers (normally 151.Nm netstat 152interprets addresses and attempts to display them 153symbolically). 154This option may be used with any of the display formats. 155.It Fl p Ar protocol 156Show statistics about 157.Ar protocol , 158which is either a well-known name for a protocol or an alias for it. Some 159protocol names and aliases are listed in the file 160.Pa /etc/protocols . 161A null response typically means that there are no interesting numbers to 162report. 163The program will complain if 164.Ar protocol 165is unknown or if there is no statistics routine for it. 166.It Fl s 167Show per-protocol statistics. 168If this option is repeated, counters with a value of zero are suppressed. 169.It Fl r 170Show the routing tables. 171When 172.Fl s 173is also present, show routing statistics instead. 174.It Fl w Ar wait 175Show network interface statistics at intervals of 176.Ar wait 177seconds. 178.El 179.Pp 180The default display, for active sockets, shows the local 181and remote addresses, send and receive queue sizes (in bytes), protocol, 182and the internal state of the protocol. 183Address formats are of the form ``host.port'' or ``network.port'' 184if a socket's address specifies a network but no specific host address. 185When known the host and network addresses are displayed symbolically 186according to the data bases 187.Pa /etc/hosts 188and 189.Pa /etc/networks , 190respectively. If a symbolic name for an address is unknown, or if 191the 192.Fl n 193option is specified, the address is printed numerically, according 194to the address family. 195For more information regarding 196the Internet ``dot format,'' 197refer to 198.Xr inet 3 ) . 199Unspecified, 200or ``wildcard'', addresses and ports appear as ``*''. 201.Pp 202The interface display provides a table of cumulative 203statistics regarding packets transferred, errors, and collisions. 204The network addresses of the interface 205and the maximum transmission unit (``mtu'') are also displayed. 206.Pp 207The routing table display indicates the available routes and 208their status. Each route consists of a destination host or network 209and a gateway to use in forwarding packets. The flags field shows 210a collection of information about the route stored as 211binary choices. The individual flags are discussed in more 212detail in the 213.Xr route 8 214and 215.Xr route 4 216manual pages. 217The mapping between letters and flags is: 218.Bl -column XXXX RTF_BLACKHOLE 2191 RTF_PROTO2 Protocol specific routing flag #1 2202 RTF_PROTO1 Protocol specific routing flag #2 221B RTF_BLACKHOLE Just discard pkts (during updates) 222C RTF_CLONING Generate new routes on use 223D RTF_DYNAMIC Created dynamically (by redirect) 224G RTF_GATEWAY Destination requires forwarding by intermediary 225H RTF_HOST Host entry (net otherwise) 226L RTF_LLINFO Valid protocol to link address translation. 227M RTF_MODIFIED Modified dynamically (by redirect) 228R RTF_REJECT Host or net unreachable 229S RTF_STATIC Manually added 230U RTF_UP Route usable 231X RTF_XRESOLVE External daemon translates proto to link address 232.El 233.Pp 234Direct routes are created for each 235interface attached to the local host; 236the gateway field for such entries shows the address of the outgoing interface. 237The refcnt field gives the 238current number of active uses of the route. Connection oriented 239protocols normally hold on to a single route for the duration of 240a connection while connectionless protocols obtain a route while sending 241to the same destination. 242The use field provides a count of the number of packets 243sent using that route. The interface entry indicates the network 244interface utilized for the route. 245.Pp 246When 247.Nm netstat 248is invoked with the 249.Fl w 250option and a 251.Ar wait 252interval argument, it displays a running count of statistics related to 253network interfaces. 254An obsolescent version of this option used a numeric parameter 255with no option, and is currently supported for backward compatibility. 256This display consists of a column for the primary interface (the first 257interface found during autoconfiguration) and a column summarizing 258information for all interfaces. 259The primary interface may be replaced with another interface with the 260.Fl I 261option. 262The first line of each screen of information contains a summary since the 263system was last rebooted. Subsequent lines of output show values 264accumulated over the preceding interval. 265.Sh SEE ALSO 266.Xr iostat 1 , 267.Xr nfsstat 1 , 268.Xr ps 1 , 269.Xr vmstat 1 , 270.Xr hosts 5 , 271.Xr networks 5 , 272.Xr protocols 5 , 273.Xr services 5 , 274.Xr trpt 8 , 275.Xr trsp 8 276.Sh HISTORY 277The 278.Nm netstat 279command appeared in 280.Bx 4.2 . 281.\" .Sh FILES 282.\" .Bl -tag -width /dev/kmem -compact 283.\" .It Pa /kernel 284.\" default kernel namelist 285.\" .It Pa /dev/kmem 286.\" default memory file 287.\" .El 288.Sh BUGS 289The notion of errors is ill-defined. 290