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 bdghimnrs 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 bdn 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 b 91With either interface display (option 92.Fl i 93or an interval, as described below), 94show the number of bytes in and out. 95.It Fl d 96With either interface display (option 97.Fl i 98or an interval, as described below), 99show the number of dropped packets. 100.It Fl f Ar address_family 101Limit statistics or address control block reports to those 102of the specified 103.Ar address family . 104The following address families 105are recognized: 106.Ar inet , 107for 108.Dv AF_INET , 109.Ar ns , 110for 111.Dv AF_NS , 112.Ar iso , 113for 114.Dv AF_ISO , 115and 116.Ar unix , 117for 118.Dv AF_UNIX . 119.It Fl g 120Show information related to multicast (group address) routing. 121By default, show the IP Multicast virtual-interface and routing tables. 122If the 123.Fl s 124option is also present, show multicast routing statistics. 125.It Fl h 126Show the state of the 127.Tn IMP 128host table (obsolete). 129.It Fl I Ar interface 130Show information about the specified interface; 131used with a 132.Ar wait 133interval as described below. 134.It Fl i 135Show the state of interfaces which have been auto-configured 136(interfaces statically configured into a system, but not 137located at boot time are not shown). 138If the 139.Fl a 140options is also present, multicast addresses currently in use are shown 141for each Ethernet interface and for each IP interface address. 142Multicast addresses are shown on separate lines following the interface 143address with which they are associated. 144.It Fl M 145Extract values associated with the name list from the specified core 146instead of the default 147.Pa /dev/kmem . 148.It Fl m 149Show statistics recorded by the memory management routines 150(the network manages a private pool of memory buffers). 151.It Fl N 152Extract the name list from the specified system instead of the default 153.Pa /kernel . 154.It Fl n 155Show network addresses as numbers (normally 156.Nm netstat 157interprets addresses and attempts to display them 158symbolically). 159This option may be used with any of the display formats. 160.It Fl p Ar protocol 161Show statistics about 162.Ar protocol , 163which is either a well-known name for a protocol or an alias for it. Some 164protocol names and aliases are listed in the file 165.Pa /etc/protocols . 166A null response typically means that there are no interesting numbers to 167report. 168The program will complain if 169.Ar protocol 170is unknown or if there is no statistics routine for it. 171.It Fl s 172Show per-protocol statistics. 173If this option is repeated, counters with a value of zero are suppressed. 174.It Fl r 175Show the routing tables. 176When 177.Fl s 178is also present, show routing statistics instead. 179.It Fl w Ar wait 180Show network interface statistics at intervals of 181.Ar wait 182seconds. 183.El 184.Pp 185The default display, for active sockets, shows the local 186and remote addresses, send and receive queue sizes (in bytes), protocol, 187and the internal state of the protocol. 188Address formats are of the form ``host.port'' or ``network.port'' 189if a socket's address specifies a network but no specific host address. 190When known the host and network addresses are displayed symbolically 191according to the data bases 192.Pa /etc/hosts 193and 194.Pa /etc/networks , 195respectively. If a symbolic name for an address is unknown, or if 196the 197.Fl n 198option is specified, the address is printed numerically, according 199to the address family. 200For more information regarding 201the Internet ``dot format,'' 202refer to 203.Xr inet 3 ) . 204Unspecified, 205or ``wildcard'', addresses and ports appear as ``*''. 206.Pp 207The interface display provides a table of cumulative 208statistics regarding packets transferred, errors, and collisions. 209The network addresses of the interface 210and the maximum transmission unit (``mtu'') are also displayed. 211.Pp 212The routing table display indicates the available routes and 213their status. Each route consists of a destination host or network 214and a gateway to use in forwarding packets. The flags field shows 215a collection of information about the route stored as 216binary choices. The individual flags are discussed in more 217detail in the 218.Xr route 8 219and 220.Xr route 4 221manual pages. 222The mapping between letters and flags is: 223.Bl -column XXXX RTF_BLACKHOLE 2241 RTF_PROTO2 Protocol specific routing flag #1 2252 RTF_PROTO1 Protocol specific routing flag #2 2263 RTF_PROTO3 Protocol specific routing flag #3 227B RTF_BLACKHOLE Just discard pkts (during updates) 228C RTF_CLONING Generate new routes on use 229c RTF_PRCLONING Protocol-specified generate new routes on use 230D RTF_DYNAMIC Created dynamically (by redirect) 231G RTF_GATEWAY Destination requires forwarding by intermediary 232H RTF_HOST Host entry (net otherwise) 233L RTF_LLINFO Valid protocol to link address translation 234M RTF_MODIFIED Modified dynamically (by redirect) 235R RTF_REJECT Host or net unreachable 236S RTF_STATIC Manually added 237U RTF_UP Route usable 238W RTF_WASCLONED Route was generated as a result of cloning 239X RTF_XRESOLVE External daemon translates proto to link address 240.El 241.Pp 242Direct routes are created for each 243interface attached to the local host; 244the gateway field for such entries shows the address of the outgoing interface. 245The refcnt field gives the 246current number of active uses of the route. Connection oriented 247protocols normally hold on to a single route for the duration of 248a connection while connectionless protocols obtain a route while sending 249to the same destination. 250The use field provides a count of the number of packets 251sent using that route. The interface entry indicates the network 252interface utilized for the route. 253.Pp 254When 255.Nm netstat 256is invoked with the 257.Fl w 258option and a 259.Ar wait 260interval argument, it displays a running count of statistics related to 261network interfaces. 262An obsolescent version of this option used a numeric parameter 263with no option, and is currently supported for backward compatibility. 264This display consists of a column for the primary interface (the first 265interface found during autoconfiguration) and a column summarizing 266information for all interfaces. 267The primary interface may be replaced with another interface with the 268.Fl I 269option. 270The first line of each screen of information contains a summary since the 271system was last rebooted. Subsequent lines of output show values 272accumulated over the preceding interval. 273.Sh SEE ALSO 274.Xr iostat 1 , 275.Xr nfsstat 1 , 276.Xr ps 1 , 277.Xr vmstat 1 , 278.Xr hosts 5 , 279.Xr networks 5 , 280.Xr protocols 5 , 281.Xr services 5 , 282.Xr trpt 8 , 283.Xr trsp 8 284.Sh HISTORY 285The 286.Nm netstat 287command appeared in 288.Bx 4.2 . 289.\" .Sh FILES 290.\" .Bl -tag -width /dev/kmem -compact 291.\" .It Pa /kernel 292.\" default kernel namelist 293.\" .It Pa /dev/kmem 294.\" default memory file 295.\" .El 296.Sh BUGS 297The notion of errors is ill-defined. 298