xref: /freebsd/usr.bin/netstat/netstat.1 (revision 17d6c636720d00f77e5d098daf4c278f89d84f7b)
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.\" $FreeBSD$
34.\"
35.Dd September 7, 2001
36.Dt NETSTAT 1
37.Os
38.Sh NAME
39.Nm netstat
40.Nd show network status
41.Sh DESCRIPTION
42The
43.Nm
44command symbolically displays the contents of various network-related
45data structures.
46There are a number of output formats,
47depending on the options for the information presented.
48.Bl -tag -width indent
49.It Xo
50.Bk -words
51.Nm
52.Op Fl AaLnSW
53.Op Fl f Ar protocol_family | Fl p Ar protocol
54.Op Fl M Ar core
55.Op Fl N Ar system
56.Ek
57.Xc
58Display a list of active sockets
59(protocol control blocks)
60for each network protocol,
61for a particular
62.Ar protocol_family ,
63or for a single
64.Ar protocol .
65If
66.Fl A
67is also present,
68show the address of a protocol control block (PCB)
69associated with a socket; used for debugging.
70If
71.Fl a
72is also present,
73show the state of all sockets;
74normally sockets used by server processes are not shown.
75If
76.Fl L
77is also present,
78show the size of the various listen queues.
79The first count shows the number of unaccepted connections,
80the second count shows the amount of unaccepted incomplete connections,
81and the third count is the maximum number of queued connections.
82If
83.Fl S
84is also present,
85show network addresses as numbers (as with
86.Fl n )
87but show ports symbolically.
88.It Xo
89.Bk -words
90.Nm
91.Fl i | I Ar interface
92.Op Fl abdnt
93.Op Fl f Ar address_family
94.Op Fl M Ar core
95.Op Fl N Ar system
96.Ek
97.Xc
98Show the state of all network interfaces or a single
99.Ar interface
100which have been auto-configured
101(interfaces statically configured into a system, but not
102located at boot time are not shown).
103An asterisk
104.Pq Dq Li *
105after an interface name indicates that the interface is
106.Dq down .
107If
108.Fl a
109is also present, multicast addresses currently in use are shown
110for each Ethernet interface and for each IP interface address.
111Multicast addresses are shown on separate lines following the interface
112address with which they are associated.
113If
114.Fl b
115is also present, show the number of bytes in and out.
116If
117.Fl d
118is also present, show the number of dropped packets.
119If
120.Fl t
121is also present, show the contents of watchdog timers.
122.It Xo
123.Bk -words
124.Nm
125.Fl w Ar wait
126.Op Fl I Ar interface
127.Op Fl d
128.Op Fl M Ar core
129.Op Fl N Ar system
130.Ek
131.Xc
132At intervals of
133.Ar wait
134seconds,
135display the information regarding packet
136traffic on all configured network interfaces
137or a single
138.Ar interface .
139If
140.Fl d
141is also present, show the number of dropped packets.
142.It Xo
143.Bk -words
144.Nm
145.Fl s Op Fl s
146.Op Fl z
147.Op Fl f Ar protocol_family | Fl p Ar protocol
148.Op Fl M Ar core
149.Op Fl N Ar system
150.Ek
151.Xc
152Display system-wide statistics for each network protocol,
153for a particular
154.Ar protocol_family ,
155or for a single
156.Ar protocol .
157If
158.Fl s
159is repeated, counters with a value of zero are suppressed.
160If
161.Fl z
162is also present, reset statistic counters after displaying them.
163.It Xo
164.Bk -words
165.Nm
166.Fl i | I Ar interface Fl s
167.Op Fl f Ar protocol_family | Fl p Ar protocol
168.Op Fl M Ar core
169.Op Fl N Ar system
170.Ek
171.Xc
172Display per-interface statistics for each network protocol,
173for a particular
174.Ar protocol_family ,
175or for a single
176.Ar protocol .
177.It Xo
178.Bk -words
179.Nm
180.Fl m
181.Op Fl M Ar core
182.Op Fl N Ar system
183.Ek
184.Xc
185Show statistics recorded by the memory management routines
186.Pq Xr mbuf 9 .
187The network manages a private pool of memory buffers.
188.It Xo
189.Bk -words
190.Nm
191.Fl r
192.Op Fl AanW
193.Op Fl f Ar address_family
194.Op Fl M Ar core
195.Op Fl N Ar system
196.Ek
197.Xc
198Display the contents of all routing tables,
199or a routing table for a particular
200.Ar address_family .
201If
202.Fl A
203is also present,
204show the contents of the internal Patricia tree
205structures; used for debugging.
206If
207.Fl a
208is also present,
209show protocol-cloned routes
210(routes generated by an
211.Dv RTF_PRCLONING
212parent route);
213normally these routes are not shown.
214When
215.Fl W
216is also present,
217show the path MTU
218for each route.
219.It Xo
220.Bk -words
221.Nm
222.Fl rs
223.Op Fl s
224.Op Fl M Ar core
225.Op Fl N Ar system
226.Ek
227.Xc
228Display routing statistics.
229If
230.Fl s
231is repeated, counters with a value of zero are suppressed.
232.It Xo
233.Bk -words
234.Nm
235.Fl g
236.Op Fl W
237.Op Fl f Ar address_family
238.Op Fl M Ar core
239.Op Fl N Ar system
240.Ek
241.Xc
242Show information related to multicast (group address) routing.
243By default, show the IP Multicast virtual-interface and routing tables.
244.It Xo
245.Bk -words
246.Nm
247.Fl gs
248.Op Fl s
249.Op Fl f Ar address_family
250.Op Fl M Ar core
251.Op Fl N Ar system
252.Ek
253.Xc
254Show multicast routing statistics.
255If
256.Fl s
257is repeated, counters with a value of zero are suppressed.
258.El
259.Pp
260Some options have the general meaning:
261.Bl -tag -width flag
262.It Fl f Ar address_family , Fl p Ar protocol
263Limit display to those records
264of the specified
265.Ar address_family
266or a single
267.Ar protocol .
268The following address families and protocols are recognized:
269.Pp
270.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
271.It Em Family
272.Em Protocols
273.It Cm inet Pq Dv AF_INET
274.Cm bdg , divert , icmp , igmp , ip , ipsec , tcp , udp
275.It Cm inet6 Pq Dv AF_INET6
276.Cm bdg , icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
277.It Cm pfkey Pq Dv PF_KEY
278.Cm pfkey
279.It Cm atalk Pq Dv AF_APPLETALK
280.Cm ddp
281.It Cm netgraph , ng Pq Dv AF_NETGRAPH
282.Cm ctrl , data
283.It Cm ipx Pq Dv AF_IPX
284.Cm ipx , spx
285.\".It Cm ns Pq Dv AF_NS
286.\".Cm idp , ns_err , spp
287.\".It Cm iso Pq Dv AF_ISO
288.\".Cm clnp , cltp , esis , tp
289.It Cm unix Pq Dv AF_UNIX
290.It Cm link Pq Dv AF_LINK
291.El
292.Pp
293The program will complain if
294.Ar protocol
295is unknown or if there is no statistics routine for it.
296.It Fl M
297Extract values associated with the name list from the specified core
298instead of the default
299.Pa /dev/kmem .
300.It Fl N
301Extract the name list from the specified system instead of the default,
302which is the kernel image the system has booted from.
303.It Fl n
304Show network addresses and ports as numbers.
305Normally
306.Nm
307attempts to resolve addresses and ports,
308and display them symbolically.
309.It Fl W
310In certain displays, avoid truncating addresses even if this causes
311some fields to overflow.
312.El
313.Pp
314The default display, for active sockets, shows the local
315and remote addresses, send and receive queue sizes (in bytes), protocol,
316and the internal state of the protocol.
317Address formats are of the form
318.Dq host.port
319or
320.Dq network.port
321if a socket's address specifies a network but no specific host address.
322When known, the host and network addresses are displayed symbolically
323according to the databases
324.Xr hosts 5
325and
326.Xr networks 5 ,
327respectively.
328If a symbolic name for an address is unknown, or if
329the
330.Fl n
331option is specified, the address is printed numerically, according
332to the address family.
333For more information regarding
334the Internet IPv4
335.Dq dot format ,
336refer to
337.Xr inet 3 .
338Unspecified,
339or
340.Dq wildcard ,
341addresses and ports appear as
342.Dq Li * .
343.Pp
344The interface display provides a table of cumulative
345statistics regarding packets transferred, errors, and collisions.
346The network addresses of the interface
347and the maximum transmission unit
348.Pq Dq mtu
349are also displayed.
350.Pp
351The routing table display indicates the available routes and their status.
352Each route consists of a destination host or network, and a gateway to use
353in forwarding packets.
354The flags field shows a collection of information about the route stored
355as binary choices.
356The individual flags are discussed in more detail in the
357.Xr route 8
358and
359.Xr route 4
360manual pages.
361The mapping between letters and flags is:
362.Bl -column ".Li W" ".Dv RTF_WASCLONED"
363.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
364.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
365.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
366.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
367.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
368.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
369.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
370.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
371.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
372.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
373.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
374.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
375.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
376.It Li S Ta Dv RTF_STATIC Ta "Manually added"
377.It Li U Ta Dv RTF_UP Ta "Route usable"
378.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
379.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
380.El
381.Pp
382Direct routes are created for each
383interface attached to the local host;
384the gateway field for such entries shows the address of the outgoing interface.
385The refcnt field gives the
386current number of active uses of the route.
387Connection oriented
388protocols normally hold on to a single route for the duration of
389a connection while connectionless protocols obtain a route while sending
390to the same destination.
391The use field provides a count of the number of packets
392sent using that route.
393The interface entry indicates the network interface utilized for the route.
394.Pp
395When
396.Nm
397is invoked with the
398.Fl w
399option and a
400.Ar wait
401interval argument, it displays a running count of statistics related to
402network interfaces.
403An obsolescent version of this option used a numeric parameter
404with no option, and is currently supported for backward compatibility.
405By default, this display summarizes information for all interfaces.
406Information for a specific interface may be displayed with the
407.Fl I
408option.
409.Sh SEE ALSO
410.Xr fstat 1 ,
411.Xr nfsstat 1 ,
412.Xr ps 1 ,
413.Xr sockstat 1 ,
414.Xr inet 4 ,
415.Xr route 4 ,
416.Xr unix 4 ,
417.Xr hosts 5 ,
418.Xr networks 5 ,
419.Xr protocols 5 ,
420.Xr services 5 ,
421.Xr iostat 8 ,
422.Xr route 8 ,
423.Xr trpt 8 ,
424.Xr vmstat 8 ,
425.Xr mbuf 9
426.Sh HISTORY
427The
428.Nm
429command appeared in
430.Bx 4.2 .
431.Pp
432IPv6 support was added by WIDE/KAME project.
433.Sh BUGS
434The notion of errors is ill-defined.
435