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.\" $FreeBSD$ 34.\" 35.Dd April 18, 1994 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 Fl M Ar core 46.Op Fl N Ar system 47.Nm netstat 48.Op Fl bdghimnrs 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 bdn 54.Op Fl I 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. 91With the routing table display (option 92.Fl r 93, as described below), show protocol-cloned routes (routes 94generated by a RTF_PRCLONING parent route); normally these routes are 95not shown. 96.It Fl b 97With the interface display (option 98.Fl i 99, as described below), 100show the number of bytes in and out. 101.It Fl d 102With either interface display (option 103.Fl i 104or an interval, as described below), 105show the number of dropped packets. 106.It Fl f Ar address_family 107Limit statistics or address control block reports to those 108of the specified 109.Ar address family . 110The following address families 111are recognized: 112.Ar inet , 113for 114.Dv AF_INET , 115.Ar ipx , 116for 117.Dv AF_IPX , 118.Ar atalk , 119for 120.Dv AF_APPLETALK (ddp) , 121.\".Ar ns , 122.\"for 123.\".Dv AF_NS , 124.\".Ar iso , 125.\"for 126.\".Dv AF_ISO , 127and 128.Ar unix , 129for 130.Dv AF_UNIX . 131.It Fl g 132Show information related to multicast (group address) routing. 133By default, show the IP Multicast virtual-interface and routing tables. 134If the 135.Fl s 136option is also present, show multicast routing statistics. 137.It Fl h 138Show the state of the 139.Tn IMP 140host table (obsolete). 141.It Fl I Ar interface 142Show information about the specified interface; 143used with a 144.Ar wait 145interval as described below. 146.It Fl i 147Show the state of interfaces which have been auto-configured 148(interfaces statically configured into a system, but not 149located at boot time are not shown). 150If the 151.Fl a 152options is also present, multicast addresses currently in use are shown 153for each Ethernet interface and for each IP interface address. 154Multicast addresses are shown on separate lines following the interface 155address with which they are associated. 156.It Fl M 157Extract values associated with the name list from the specified core 158instead of the default 159.Pa /dev/kmem . 160.It Fl m 161Show statistics recorded by the memory management routines 162(the network manages a private pool of memory buffers). 163.It Fl N 164Extract the name list from the specified system instead of the default 165.Pa /kernel . 166.It Fl n 167Show network addresses as numbers (normally 168.Nm netstat 169interprets addresses and attempts to display them 170symbolically). 171This option may be used with any of the display formats. 172.It Fl p Ar protocol 173Show statistics about 174.Ar protocol , 175which is either a well-known name for a protocol or an alias for it. Some 176protocol names and aliases are listed in the file 177.Pa /etc/protocols . 178The special protocol name ``bdg'' 179is used to show bridging statistics. 180A null response typically means that there are no interesting numbers to 181report. 182The program will complain if 183.Ar protocol 184is unknown or if there is no statistics routine for it. 185.It Fl s 186Show per-protocol statistics. 187If this option is repeated, counters with a value of zero are suppressed. 188.It Fl r 189Show the routing tables. 190Use with 191.Fl a 192to show protocol-cloned routes. 193When 194.Fl s 195is also present, show routing statistics instead. 196.It Fl w Ar wait 197Show network interface statistics at intervals of 198.Ar wait 199seconds. 200.El 201.Pp 202The default display, for active sockets, shows the local 203and remote addresses, send and receive queue sizes (in bytes), protocol, 204and the internal state of the protocol. 205Address formats are of the form ``host.port'' or ``network.port'' 206if a socket's address specifies a network but no specific host address. 207When known the host and network addresses are displayed symbolically 208according to the data bases 209.Pa /etc/hosts 210and 211.Pa /etc/networks , 212respectively. If a symbolic name for an address is unknown, or if 213the 214.Fl n 215option is specified, the address is printed numerically, according 216to the address family. 217For more information regarding 218the Internet ``dot format,'' 219refer to 220.Xr inet 3 ) . 221Unspecified, 222or ``wildcard'', addresses and ports appear as ``*''. 223.Pp 224The interface display provides a table of cumulative 225statistics regarding packets transferred, errors, and collisions. 226The network addresses of the interface 227and the maximum transmission unit (``mtu'') are also displayed. 228.Pp 229The routing table display indicates the available routes and 230their status. Each route consists of a destination host or network 231and a gateway to use in forwarding packets. The flags field shows 232a collection of information about the route stored as 233binary choices. The individual flags are discussed in more 234detail in the 235.Xr route 8 236and 237.Xr route 4 238manual pages. 239The mapping between letters and flags is: 240.Bl -column XXXX RTF_BLACKHOLE 2411 RTF_PROTO1 Protocol specific routing flag #1 2422 RTF_PROTO2 Protocol specific routing flag #2 2433 RTF_PROTO3 Protocol specific routing flag #3 244B RTF_BLACKHOLE Just discard pkts (during updates) 245b RTF_BROADCAST The route represents a broadcast address 246C RTF_CLONING Generate new routes on use 247c RTF_PRCLONING Protocol-specified generate new routes on use 248D RTF_DYNAMIC Created dynamically (by redirect) 249G RTF_GATEWAY Destination requires forwarding by intermediary 250H RTF_HOST Host entry (net otherwise) 251L RTF_LLINFO Valid protocol to link address translation 252M RTF_MODIFIED Modified dynamically (by redirect) 253R RTF_REJECT Host or net unreachable 254S RTF_STATIC Manually added 255U RTF_UP Route usable 256W RTF_WASCLONED Route was generated as a result of cloning 257X RTF_XRESOLVE External daemon translates proto to link address 258.El 259.Pp 260Direct routes are created for each 261interface attached to the local host; 262the gateway field for such entries shows the address of the outgoing interface. 263The refcnt field gives the 264current number of active uses of the route. Connection oriented 265protocols normally hold on to a single route for the duration of 266a connection while connectionless protocols obtain a route while sending 267to the same destination. 268The use field provides a count of the number of packets 269sent using that route. The interface entry indicates the network 270interface utilized for the route. 271.Pp 272When 273.Nm netstat 274is invoked with the 275.Fl w 276option and a 277.Ar wait 278interval argument, it displays a running count of statistics related to 279network interfaces. 280An obsolescent version of this option used a numeric parameter 281with no option, and is currently supported for backward compatibility. 282By default, this display summarizes information for all interfaces. 283Information for a specific interface may be displayed with the 284.Fl I 285option. 286.Sh SEE ALSO 287.Xr fstat 1 , 288.Xr nfsstat 1 , 289.Xr sockstat 1 , 290.Xr ps 1 , 291.Xr inet 4 , 292.Xr unix 4 , 293.Xr hosts 5 , 294.Xr networks 5 , 295.Xr protocols 5 , 296.Xr services 5 , 297.Xr iostat 8 , 298.Xr trpt 8 , 299.Xr vmstat 8 300.Sh HISTORY 301The 302.Nm netstat 303command appeared in 304.Bx 4.2 . 305.\" .Sh FILES 306.\" .Bl -tag -width /dev/kmem -compact 307.\" .It Pa /kernel 308.\" default kernel namelist 309.\" .It Pa /dev/kmem 310.\" default memory file 311.\" .El 312.Sh BUGS 313The notion of errors is ill-defined. 314