1.\" $NetBSD: netstat.1,v 1.11 1995/10/03 21:42:43 thorpej 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.\" from: @(#)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 netstat 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 netstat 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 netstat 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 netstat 60.Op Fl p Ar protocol 61.Op Fl M Ar core 62.Op Fl N Ar system 63.Sh DESCRIPTION 64The 65.Nm netstat 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 netstat 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 , 112and 113.Ar unix , 114for 115.Dv AF_UNIX . 116.It Fl g 117Show information related to multicast (group address) routing. 118By default, show the IP Multicast virtual-interface and routing tables. 119If the 120.Fl s 121option is also present, show multicast routing statistics. 122.It Fl h 123Show the state of the 124.Tn IMP 125host table (obsolete). 126.It Fl I Ar interface 127Show information about the specified interface; 128used with a 129.Ar wait 130interval as described below. 131.It Fl i 132Show the state of interfaces which have been auto-configured 133(interfaces statically configured into a system, but not 134located at boot time are not shown). 135If the 136.Fl a 137options is also present, multicast addresses currently in use are shown 138for each Ethernet interface and for each IP interface address. 139Multicast addresses are shown on separate lines following the interface 140address with which they are associated. 141.It Fl M 142Extract values associated with the name list from the specified core 143instead of the default 144.Pa /dev/kmem . 145.It Fl m 146Show statistics recorded by the memory management routines 147(the network manages a private pool of memory buffers). 148.It Fl N 149Extract the name list from the specified system instead of the default 150.Pa /netbsd . 151.It Fl n 152Show network addresses as numbers (normally 153.Nm netstat 154interprets addresses and attempts to display them 155symbolically). 156This option may be used with any of the display formats. 157.It Fl p Ar protocol 158Show statistics about 159.Ar protocol , 160which is either a well-known name for a protocol or an alias for it. Some 161protocol names and aliases are listed in the file 162.Pa /etc/protocols . 163A null response typically means that there are no interesting numbers to 164report. 165The program will complain if 166.Ar protocol 167is unknown or if there is no statistics routine for it. 168.It Fl s 169Show per-protocol statistics. 170If this option is repeated, counters with a value of zero are suppressed. 171.It Fl r 172Show the routing tables. 173When 174.Fl s 175is also present, show routing statistics instead. 176.It Fl w Ar wait 177Show network interface statistics at intervals of 178.Ar wait 179seconds. 180.El 181.Pp 182The default display, for active sockets, shows the local 183and remote addresses, send and receive queue sizes (in bytes), protocol, 184and the internal state of the protocol. 185Address formats are of the form ``host.port'' or ``network.port'' 186if a socket's address specifies a network but no specific host address. 187When known the host and network addresses are displayed symbolically 188according to the data bases 189.Pa /etc/hosts 190and 191.Pa /etc/networks , 192respectively. If a symbolic name for an address is unknown, or if 193the 194.Fl n 195option is specified, the address is printed numerically, according 196to the address family. 197For more information regarding 198the Internet ``dot format,'' 199refer to 200.Xr inet 3 ) . 201Unspecified, 202or ``wildcard'', addresses and ports appear as ``*''. 203.Pp 204The interface display provides a table of cumulative 205statistics regarding packets transferred, errors, and collisions. 206The network addresses of the interface 207and the maximum transmission unit (``mtu'') are also displayed. 208.Pp 209The routing table display indicates the available routes and 210their status. Each route consists of a destination host or network 211and a gateway to use in forwarding packets. The flags field shows 212a collection of information about the route stored as 213binary choices. The individual flags are discussed in more 214detail in the 215.Xr route 8 216and 217.Xr route 4 218manual pages. 219The mapping between letters and flags is: 220.Bl -column XXXX RTF_BLACKHOLE 2211 RTF_PROTO2 Protocol specific routing flag #1 2222 RTF_PROTO1 Protocol specific routing flag #2 223B RTF_BLACKHOLE Just discard pkts (during updates) 224C RTF_CLONING Generate new routes on use 225D RTF_DYNAMIC Created dynamically (by redirect) 226G RTF_GATEWAY Destination requires forwarding by intermediary 227H RTF_HOST Host entry (net otherwise) 228L RTF_LLINFO Valid protocol to link address translation. 229M RTF_MODIFIED Modified dynamically (by redirect) 230R RTF_REJECT Host or net unreachable 231S RTF_STATIC Manually added 232U RTF_UP Route usable 233X RTF_XRESOLVE External daemon translates proto to link address 234.El 235.Pp 236Direct routes are created for each 237interface attached to the local host; 238the gateway field for such entries shows the address of the outgoing interface. 239The refcnt field gives the 240current number of active uses of the route. Connection oriented 241protocols normally hold on to a single route for the duration of 242a connection while connectionless protocols obtain a route while sending 243to the same destination. 244The use field provides a count of the number of packets 245sent using that route. The mtu entry shows the mtu associated with 246that route. This mtu value is used as the basis for the TCP maximum 247segment size. A 248.Sq - 249indicates that the mtu for this route has not been set, and a default 250TCP maximum segment size will be used. The interface entry indicates 251the network interface utilized for the route. 252.Pp 253When 254.Nm netstat 255is invoked with the 256.Fl w 257option and a 258.Ar wait 259interval argument, it displays a running count of statistics related to 260network interfaces. 261An obsolescent version of this option used a numeric parameter 262with no option, and is currently supported for backward compatibility. 263This display consists of a column for the primary interface (the first 264interface found during autoconfiguration) and a column summarizing 265information for all interfaces. 266The primary interface may be replaced with another interface with the 267.Fl I 268option. 269The first line of each screen of information contains a summary since the 270system was last rebooted. Subsequent lines of output show values 271accumulated over the preceding interval. 272.Sh SEE ALSO 273.Xr nfsstat 1 , 274.Xr ps 1 , 275.Xr hosts 5 , 276.Xr networks 5 , 277.Xr protocols 5 , 278.Xr services 5 , 279.Xr trpt 8 , 280.Xr trsp 8 , 281.Xr iostat 8 , 282.Xr vmstat 8 283.Sh HISTORY 284The 285.Nm netstat 286command appeared in 287.Bx 4.2 . 288.\" .Sh FILES 289.\" .Bl -tag -width /dev/kmem -compact 290.\" .It Pa /netbsd 291.\" default kernel namelist 292.\" .It Pa /dev/kmem 293.\" default memory file 294.\" .El 295.Sh BUGS 296The notion of errors is ill-defined. 297