1.\" $NetBSD: netstat.1,v 1.20 1999/03/14 18:30:04 kristerw 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 dgimnrsv 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.Nm "" 64.Op Fl p Ar protocol 65.Op Fl M Ar core 66.Op Fl N Ar system 67.Fl P Ar pcbaddr 68.Sh DESCRIPTION 69The 70.Nm 71command symbolically displays the contents of various network-related 72data structures. 73There are a number of output formats, 74depending on the options for the information presented. 75The first form of the command displays a list of active sockets for 76each protocol. 77The second form presents the contents of one of the other network 78data structures according to the option selected. 79Using the third form, with a 80.Ar wait 81interval specified, 82.Nm 83will continuously display the information regarding packet 84traffic on the configured network interfaces. 85The fourth form displays statistics about the named protocol. 86.Pp 87The options have the following meaning: 88.Bl -tag -width flag 89.It Fl A 90With the default display, 91show the address of any protocol control blocks associated with sockets; used 92for debugging. 93.It Fl a 94With the default display, 95show the state of all sockets; normally sockets used by 96server processes are not shown. 97.It Fl b 98With the interface display (option 99.Fl i ) , 100show bytes in and out, instead of packets 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 ns , 116for 117.Dv AF_NS ; 118.Ar iso , 119for 120.Dv AF_ISO ; 121.Ar atalk , 122for 123.Dv AF_APPLETALK ; 124and 125.Ar local 126or 127.Ar unix , 128for 129.Dv AF_LOCAL . 130.It Fl g 131Show information related to multicast (group address) routing. 132By default, show the IP Multicast virtual-interface and routing tables. 133If the 134.Fl s 135option is also present, show multicast routing statistics. 136.It Fl I Ar interface 137Show information about the specified interface; 138used with a 139.Ar wait 140interval as described below. 141.It Fl i 142Show the state of interfaces which have been auto-configured 143(interfaces statically configured into a system, but not 144located at boot time are not shown). 145If the 146.Fl a 147options is also present, multicast addresses currently in use are shown 148for each Ethernet interface and for each IP interface address. 149Multicast addresses are shown on separate lines following the interface 150address with which they are associated. 151.It Fl M 152Extract values associated with the name list from the specified core 153instead of the default 154.Pa /dev/kmem . 155.It Fl m 156Show statistics recorded by the memory management routines 157(the network manages a private pool of memory buffers). 158.It Fl N 159Extract the name list from the specified system instead of the default 160.Pa /netbsd . 161.It Fl n 162Show network addresses as numbers (normally 163.Nm 164interprets addresses and attempts to display them 165symbolically). 166This option may be used with any of the display formats. 167.It Fl P Ar pcbaddr 168Dump the contents of the protocol control block (PCB) located at kernel 169virtual address 170.Ar pcbaddr . 171This address may be obtained using the 172.Fl A 173flag. The default protocol is TCP, but may be overridden using the 174.Fl p 175flag. 176.It Fl p Ar protocol 177Show statistics about 178.Ar protocol , 179which is either a well-known name for a protocol or an alias for it. Some 180protocol names and aliases are listed in the file 181.Pa /etc/protocols . 182A null response typically means that there are no interesting numbers to 183report. 184The program will complain if 185.Ar protocol 186is unknown or if there is no statistics routine for it. 187.It Fl s 188Show per-protocol statistics. 189If this option is repeated, counters with a value of zero are suppressed. 190.It Fl r 191Show the routing tables. 192When 193.Fl s 194is also present, show routing statistics instead. 195.It Fl v 196Show extra (verbose) detail for the routing tables. 197.It Fl w Ar wait 198Show network interface statistics at intervals of 199.Ar wait 200seconds. 201.El 202.Pp 203The default display, for active sockets, shows the local 204and remote addresses, send and receive queue sizes (in bytes), protocol, 205and the internal state of the protocol. 206Address formats are of the form ``host.port'' or ``network.port'' 207if a socket's address specifies a network but no specific host address. 208When known the host and network addresses are displayed symbolically 209according to the data bases 210.Pa /etc/hosts 211and 212.Pa /etc/networks , 213respectively. If a symbolic name for an address is unknown, or if 214the 215.Fl n 216option is specified, the address is printed numerically, according 217to the address family. 218For more information regarding 219the Internet ``dot format,'' 220refer to 221.Xr inet 3 ) . 222Unspecified, 223or ``wildcard'', addresses and ports appear as ``*''. 224.Pp 225The interface display provides a table of cumulative 226statistics regarding packets transferred, errors, and collisions. 227The network addresses of the interface 228and the maximum transmission unit (``mtu'') are also displayed. 229.Pp 230The routing table display indicates the available routes and 231their status. Each route consists of a destination host or network 232and a gateway to use in forwarding packets. The flags field shows 233a collection of information about the route stored as 234binary choices. The individual flags are discussed in more 235detail in the 236.Xr route 8 237and 238.Xr route 4 239manual pages. 240The mapping between letters and flags is: 241.Bl -column XXXX RTF_BLACKHOLE 2421 RTF_PROTO2 Protocol specific routing flag #1 2432 RTF_PROTO1 Protocol specific routing flag #2 244B RTF_BLACKHOLE Just discard pkts (during updates) 245C RTF_CLONING Generate new routes on use 246D RTF_DYNAMIC Created dynamically (by redirect) 247G RTF_GATEWAY Destination requires forwarding by intermediary 248H RTF_HOST Host entry (net otherwise) 249L RTF_LLINFO Valid protocol to link address translation. 250M RTF_MODIFIED Modified dynamically (by redirect) 251R RTF_REJECT Host or net unreachable 252S RTF_STATIC Manually added 253U RTF_UP Route usable 254X RTF_XRESOLVE External daemon translates proto to link address 255.El 256.Pp 257Direct routes are created for each 258interface attached to the local host; 259the gateway field for such entries shows the address of the outgoing interface. 260The refcnt field gives the 261current number of active uses of the route. Connection oriented 262protocols normally hold on to a single route for the duration of 263a connection while connectionless protocols obtain a route while sending 264to the same destination. 265The use field provides a count of the number of packets 266sent using that route. The mtu entry shows the mtu associated with 267that route. This mtu value is used as the basis for the TCP maximum 268segment size. The 'L' flag appended to the mtu value indicates that 269the value is locked, and that path mtu discovery is turned off for 270that route. 271A 272.Sq - 273indicates that the mtu for this route has not been set, and a default 274TCP maximum segment size will be used. The interface entry indicates 275the network interface utilized for the route. 276.Pp 277When 278.Nm 279is invoked with the 280.Fl w 281option and a 282.Ar wait 283interval argument, it displays a running count of statistics related to 284network interfaces. 285An obsolescent version of this option used a numeric parameter 286with no option, and is currently supported for backward compatibility. 287This display consists of a column for the primary interface (the first 288interface found during autoconfiguration) and a column summarizing 289information for all interfaces. 290The primary interface may be replaced with another interface with the 291.Fl I 292option. 293The first line of each screen of information contains a summary since the 294system was last rebooted. Subsequent lines of output show values 295accumulated over the preceding interval. 296.Sh SEE ALSO 297.Xr nfsstat 1 , 298.Xr ps 1 , 299.Xr hosts 5 , 300.Xr networks 5 , 301.Xr protocols 5 , 302.Xr services 5 , 303.Xr trpt 8 , 304.Xr trsp 8 , 305.Xr iostat 8 , 306.Xr vmstat 8 307.Sh HISTORY 308The 309.Nm 310command appeared in 311.Bx 4.2 . 312.\" .Sh FILES 313.\" .Bl -tag -width /dev/kmem -compact 314.\" .It Pa /netbsd 315.\" default kernel namelist 316.\" .It Pa /dev/kmem 317.\" default memory file 318.\" .El 319.Sh BUGS 320The notion of errors is ill-defined. 321