1.\" $NetBSD: netstat.1,v 1.26 1999/12/13 15:22:55 itojun 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 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 dgiLmnrsv 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.Nm "" 69.Op Fl p Ar protocol 70.Op Fl i 71.Op Fl I Ar Interface 72.Nm "" 73.Op Fl s 74.Op Fl f Ar address_family 75.Op Fl i 76.Op Fl I Ar Interface 77.Sh DESCRIPTION 78The 79.Nm 80command symbolically displays the contents of various network-related 81data structures. 82There are a number of output formats, 83depending on the options for the information presented. 84The first form of the command displays a list of active sockets for 85each protocol. 86The second form presents the contents of one of the other network 87data structures according to the option selected. 88Using the third form, with a 89.Ar wait 90interval specified, 91.Nm 92will continuously display the information regarding packet 93traffic on the configured network interfaces. 94The fourth form displays statistics about the named protocol. 95The fifth and sixth forms display per interface statistics for 96the specified protocol or address family. 97.Pp 98The options have the following meaning: 99.Bl -tag -width flag 100.It Fl A 101With the default display, 102show the address of any protocol control blocks associated with sockets; used 103for debugging. 104.It Fl a 105With the default display, 106show the state of all sockets; normally sockets used by 107server processes are not shown. 108.It Fl b 109With the interface display (option 110.Fl i ) , 111show bytes in and out, instead of packets in and out. 112.It Fl d 113With either interface display (option 114.Fl i 115or an interval, as described below), 116show the number of dropped packets. 117.It Fl f Ar address_family 118Limit statistics or address control block reports to those 119of the specified 120.Ar address family . 121The following address families 122are recognized: 123.Ar inet , 124for 125.Dv AF_INET ; 126.Ar inet6 , 127for 128.Dv AF_INET6 ; 129.Ar ns , 130for 131.Dv AF_NS ; 132.Ar iso , 133for 134.Dv AF_ISO ; 135.Ar atalk , 136for 137.Dv AF_APPLETALK ; 138and 139.Ar local 140or 141.Ar unix , 142for 143.Dv AF_LOCAL . 144.It Fl g 145Show information related to multicast (group address) routing. 146By default, show the IP Multicast virtual-interface and routing tables. 147If the 148.Fl s 149option is also present, show multicast routing statistics. 150.It Fl I Ar interface 151Show information about the specified interface; 152used with a 153.Ar wait 154interval as described below. 155If the 156.Fl f Ar address_family 157option (with the 158.Fl s 159option) or the 160.Fl p Ar protocol 161option is present, show per-interface statistics on the 162.Ar interface 163for the specfied 164.Ar address_family 165or 166.Ar protocol, 167respectively. 168.It Fl i 169Show the state of interfaces which have been auto-configured 170(interfaces statically configured into a system, but not 171located at boot time are not shown). 172If the 173.Fl a 174options is also present, multicast addresses currently in use are shown 175for each Ethernet interface and for each IP interface address. 176Multicast addresses are shown on separate lines following the interface 177address with which they are associated. 178If the 179.Fl f Ar address_family 180option (with the 181.Fl s 182option) or the 183.Fl p Ar protocol 184option is present, show per-interface statistics on all interfaces 185for the specfied 186.Ar address_family 187or 188.Ar protocol, 189respectively. 190.It Fl L 191Don't show link-level routes (e.g., IPv4 ARP or IPv6 neighbour cache). 192.It Fl M 193Extract values associated with the name list from the specified core 194instead of the default 195.Pa /dev/kmem . 196.It Fl m 197Show statistics recorded by the memory management routines 198(the network manages a private pool of memory buffers). 199.It Fl N 200Extract the name list from the specified system instead of the default 201.Pa /netbsd . 202.It Fl n 203Show network addresses as numbers (normally 204.Nm 205interprets addresses and attempts to display them 206symbolically). 207This option may be used with any of the display formats. 208.It Fl P Ar pcbaddr 209Dump the contents of the protocol control block (PCB) located at kernel 210virtual address 211.Ar pcbaddr . 212This address may be obtained using the 213.Fl A 214flag. The default protocol is TCP, but may be overridden using the 215.Fl p 216flag. 217.It Fl p Ar protocol 218Show statistics about 219.Ar protocol , 220which is either a well-known name for a protocol or an alias for it. Some 221protocol names and aliases are listed in the file 222.Pa /etc/protocols . 223A null response typically means that there are no interesting numbers to 224report. 225The program will complain if 226.Ar protocol 227is unknown or if there is no statistics routine for it. 228.It Fl s 229Show per-protocol statistics. 230If this option is repeated, counters with a value of zero are suppressed. 231.It Fl r 232Show the routing tables. 233When 234.Fl s 235is also present, show routing statistics instead. 236.It Fl v 237Show extra (verbose) detail for the routing tables 238.Pq Fl r , 239or avoid truncation of long addresses. 240.It Fl w Ar wait 241Show network interface statistics at intervals of 242.Ar wait 243seconds. 244.El 245.Pp 246The default display, for active sockets, shows the local 247and remote addresses, send and receive queue sizes (in bytes), protocol, 248and the internal state of the protocol. 249Address formats are of the form ``host.port'' or ``network.port'' 250if a socket's address specifies a network but no specific host address. 251When known the host and network addresses are displayed symbolically 252according to the data bases 253.Pa /etc/hosts 254and 255.Pa /etc/networks , 256respectively. If a symbolic name for an address is unknown, or if 257the 258.Fl n 259option is specified, the address is printed numerically, according 260to the address family. 261For more information regarding 262the Internet ``dot format,'' 263refer to 264.Xr inet 3 ) . 265Unspecified, 266or ``wildcard'', addresses and ports appear as ``*''. 267.Pp 268The interface display provides a table of cumulative 269statistics regarding packets transferred, errors, and collisions. 270The network addresses of the interface 271and the maximum transmission unit (``mtu'') are also displayed. 272.Pp 273The routing table display indicates the available routes and 274their status. Each route consists of a destination host or network 275and a gateway to use in forwarding packets. The flags field shows 276a collection of information about the route stored as 277binary choices. The individual flags are discussed in more 278detail in the 279.Xr route 8 280and 281.Xr route 4 282manual pages. 283The mapping between letters and flags is: 284.Bl -column XXXX RTF_BLACKHOLE 2851 RTF_PROTO2 Protocol specific routing flag #1 2862 RTF_PROTO1 Protocol specific routing flag #2 287B RTF_BLACKHOLE Just discard pkts (during updates) 288C RTF_CLONING Generate new routes on use 289D RTF_DYNAMIC Created dynamically (by redirect) 290G RTF_GATEWAY Destination requires forwarding by intermediary 291H RTF_HOST Host entry (net otherwise) 292L RTF_LLINFO Valid protocol to link address translation. 293M RTF_MODIFIED Modified dynamically (by redirect) 294R RTF_REJECT Host or net unreachable 295S RTF_STATIC Manually added 296U RTF_UP Route usable 297X RTF_XRESOLVE External daemon translates proto to link address 298.El 299.Pp 300Direct routes are created for each 301interface attached to the local host; 302the gateway field for such entries shows the address of the outgoing interface. 303The refcnt field gives the 304current number of active uses of the route. Connection oriented 305protocols normally hold on to a single route for the duration of 306a connection while connectionless protocols obtain a route while sending 307to the same destination. 308The use field provides a count of the number of packets 309sent using that route. The mtu entry shows the mtu associated with 310that route. This mtu value is used as the basis for the TCP maximum 311segment size. The 'L' flag appended to the mtu value indicates that 312the value is locked, and that path mtu discovery is turned off for 313that route. 314A 315.Sq - 316indicates that the mtu for this route has not been set, and a default 317TCP maximum segment size will be used. The interface entry indicates 318the network interface utilized for the route. 319.Pp 320When 321.Nm 322is invoked with the 323.Fl w 324option and a 325.Ar wait 326interval argument, it displays a running count of statistics related to 327network interfaces. 328An obsolescent version of this option used a numeric parameter 329with no option, and is currently supported for backward compatibility. 330This display consists of a column for the primary interface (the first 331interface found during autoconfiguration) and a column summarizing 332information for all interfaces. 333The primary interface may be replaced with another interface with the 334.Fl I 335option. 336The first line of each screen of information contains a summary since the 337system was last rebooted. Subsequent lines of output show values 338accumulated over the preceding interval. 339.Sh SEE ALSO 340.Xr nfsstat 1 , 341.Xr ps 1 , 342.Xr hosts 5 , 343.Xr networks 5 , 344.Xr protocols 5 , 345.Xr services 5 , 346.Xr trpt 8 , 347.Xr trsp 8 , 348.Xr iostat 8 , 349.Xr vmstat 8 350.Sh HISTORY 351The 352.Nm 353command appeared in 354.Bx 4.2 . 355IPv6 support was added by WIDE/KAME project. 356.\" .Sh FILES 357.\" .Bl -tag -width /dev/kmem -compact 358.\" .It Pa /netbsd 359.\" default kernel namelist 360.\" .It Pa /dev/kmem 361.\" default memory file 362.\" .El 363.Sh BUGS 364The notion of errors is ill-defined. 365