1.\" $NetBSD: netstat.1,v 1.14 1997/10/28 22:38:42 kml Exp $ 2.\" 3.\" Copyright (c) 1983, 1990, 1992, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)netstat.1 8.8 (Berkeley) 4/18/94 35.\" 36.Dd April 18, 1994 37.Dt NETSTAT 1 38.Os BSD 4.2 39.Sh NAME 40.Nm netstat 41.Nd show network status 42.Sh SYNOPSIS 43.Nm 44.Op Fl Aan 45.Op Fl f Ar address_family 46.Op Fl M Ar core 47.Op Fl N Ar system 48.Nm "" 49.Op Fl dghimnrs 50.Op Fl f Ar address_family 51.Op Fl M Ar core 52.Op Fl N Ar system 53.Nm "" 54.Op Fl dn 55.Op Fl I Ar interface 56.Op Fl M Ar core 57.Op Fl N Ar system 58.Op Fl w Ar wait 59.Nm "" 60.Op Fl p Ar protocol 61.Op Fl M Ar core 62.Op Fl N Ar system 63.Sh DESCRIPTION 64The 65.Nm 66command symbolically displays the contents of various network-related 67data structures. 68There are a number of output formats, 69depending on the options for the information presented. 70The first form of the command displays a list of active sockets for 71each protocol. 72The second form presents the contents of one of the other network 73data structures according to the option selected. 74Using the third form, with a 75.Ar wait 76interval specified, 77.Nm 78will continuously display the information regarding packet 79traffic on the configured network interfaces. 80The fourth form displays statistics about the named protocol. 81.Pp 82The options have the following meaning: 83.Bl -tag -width flag 84.It Fl A 85With the default display, 86show the address of any protocol control blocks associated with sockets; used 87for debugging. 88.It Fl a 89With the default display, 90show the state of all sockets; normally sockets used by 91server processes are not shown. 92.It Fl d 93With either interface display (option 94.Fl i 95or an interval, as described below), 96show the number of dropped packets. 97.It Fl f Ar address_family 98Limit statistics or address control block reports to those 99of the specified 100.Ar address family . 101The following address families 102are recognized: 103.Ar inet , 104for 105.Dv AF_INET ; 106.Ar ns , 107for 108.Dv AF_NS ; 109.Ar iso , 110for 111.Dv AF_ISO ; 112.Ar atalk , 113for 114.Dv AF_APPLETALK ; 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 /netbsd . 154.It Fl n 155Show network addresses as numbers (normally 156.Nm 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 226B RTF_BLACKHOLE Just discard pkts (during updates) 227C RTF_CLONING Generate new routes on use 228D RTF_DYNAMIC Created dynamically (by redirect) 229G RTF_GATEWAY Destination requires forwarding by intermediary 230H RTF_HOST Host entry (net otherwise) 231L RTF_LLINFO Valid protocol to link address translation. 232M RTF_MODIFIED Modified dynamically (by redirect) 233R RTF_REJECT Host or net unreachable 234S RTF_STATIC Manually added 235U RTF_UP Route usable 236X RTF_XRESOLVE External daemon translates proto to link address 237.El 238.Pp 239Direct routes are created for each 240interface attached to the local host; 241the gateway field for such entries shows the address of the outgoing interface. 242The refcnt field gives the 243current number of active uses of the route. Connection oriented 244protocols normally hold on to a single route for the duration of 245a connection while connectionless protocols obtain a route while sending 246to the same destination. 247The use field provides a count of the number of packets 248sent using that route. The mtu entry shows the mtu associated with 249that route. This mtu value is used as the basis for the TCP maximum 250segment size. The 'L' flag appended to the mtu value indicates that 251the value is locked, and that path mtu discovery is turned off for 252that route. 253A 254.Sq - 255indicates that the mtu for this route has not been set, and a default 256TCP maximum segment size will be used. The interface entry indicates 257the network interface utilized for the route. 258.Pp 259When 260.Nm 261is invoked with the 262.Fl w 263option and a 264.Ar wait 265interval argument, it displays a running count of statistics related to 266network interfaces. 267An obsolescent version of this option used a numeric parameter 268with no option, and is currently supported for backward compatibility. 269This display consists of a column for the primary interface (the first 270interface found during autoconfiguration) and a column summarizing 271information for all interfaces. 272The primary interface may be replaced with another interface with the 273.Fl I 274option. 275The first line of each screen of information contains a summary since the 276system was last rebooted. Subsequent lines of output show values 277accumulated over the preceding interval. 278.Sh SEE ALSO 279.Xr nfsstat 1 , 280.Xr ps 1 , 281.Xr hosts 5 , 282.Xr networks 5 , 283.Xr protocols 5 , 284.Xr services 5 , 285.Xr trpt 8 , 286.Xr trsp 8 , 287.Xr iostat 8 , 288.Xr vmstat 8 289.Sh HISTORY 290The 291.Nm 292command appeared in 293.Bx 4.2 . 294.\" .Sh FILES 295.\" .Bl -tag -width /dev/kmem -compact 296.\" .It Pa /netbsd 297.\" default kernel namelist 298.\" .It Pa /dev/kmem 299.\" default memory file 300.\" .El 301.Sh BUGS 302The notion of errors is ill-defined. 303