xref: /freebsd/usr.bin/netstat/netstat.1 (revision c678bc4f13a340ad88debe321afd0097db2590cb)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd April 18, 1994
36.Dt NETSTAT 1
37.Os BSD 4.2
38.Sh NAME
39.Nm netstat
40.Nd show network status
41.Sh SYNOPSIS
42.Nm
43.Op Fl AaLlnW
44.Op Fl f Ar address_family
45.Op Fl M Ar core
46.Op Fl N Ar system
47.Nm
48.Op Fl bdghilmnrs
49.Op Fl f Ar address_family
50.Op Fl M Ar core
51.Op Fl N Ar system
52.Nm
53.Op Fl bdn
54.Op Fl I Ar interface
55.Op Fl M Ar core
56.Op Fl N Ar system
57.Op Fl w Ar wait
58.Nm
59.Op Fl p Ar protocol
60.Op Fl M Ar core
61.Op Fl N Ar system
62.Nm
63.Op Fl p Ar protocol
64.Op Fl i
65.Op Fl I Ar Interface
66.Nm
67.Op Fl s
68.Op Fl f Ar address_family
69.Op Fl i
70.Op Fl I Ar Interface
71.Sh DESCRIPTION
72The
73.Nm
74command symbolically displays the contents of various network-related
75data structures.
76There are a number of output formats,
77depending on the options for the information presented.
78The first form of the command displays a list of active sockets for
79each protocol.
80The second form presents the contents of one of the other network
81data structures according to the option selected.
82Using the third form, with a
83.Ar wait
84interval specified,
85.Nm
86will continuously display the information regarding packet
87traffic on the configured network interfaces.
88The fourth form displays statistics about the named protocol.
89The fifth and sixth forms display per interface statistics for
90the specified protocol or address family.
91.Pp
92The options have the following meaning:
93.Bl -tag -width flag
94.It Fl A
95With the default display,
96show the address of any protocol control blocks associated with sockets; used
97for debugging.
98.It Fl a
99With the default display,
100show the state of all sockets; normally sockets used by
101server processes are not shown.
102With the routing table display (option
103.Fl r ,
104as described below), show protocol-cloned routes (routes
105generated by a
106.Dv RTF_PRCLONING
107parent route); normally these routes are
108not shown.
109.It Fl b
110With the interface display (option
111.Fl i
112, as described below),
113show the number of bytes in and out.
114.It Fl d
115With either interface display (option
116.Fl i
117or an interval, as described below),
118show the number of dropped packets.
119.It Fl f Ar address_family
120Limit statistics or address control block reports to those
121of the specified
122.Ar address family  .
123The following address families
124are recognized:
125.Ar inet  ,
126for
127.Dv AF_INET  ,
128.Ar inet6  ,
129for
130.Dv AF_INET6  ,
131.Ar ipx ,
132for
133.Dv AF_IPX  ,
134.Ar atalk ,
135for
136.Dv AF_APPLETALK (ddp)  ,
137.Ar netgraph
138or
139.Ar ng
140for
141.Dv AF_NETGRAPH ,
142.\".Ar ns ,
143.\"for
144.\".Dv AF_NS  ,
145.\".Ar iso ,
146.\"for
147.\".Dv AF_ISO ,
148and
149.Ar unix  ,
150for
151.Dv AF_UNIX  .
152.It Fl g
153Show information related to multicast (group address) routing.
154By default, show the IP Multicast virtual-interface and routing tables.
155If the
156.Fl s
157option is also present, show multicast routing statistics.
158.It Fl h
159Show the state of the
160.Tn IMP
161host table (obsolete).
162.It Fl I Ar interface
163Show information about the specified interface;
164used with a
165.Ar wait
166interval as described below.
167If the
168.Fl f Ar address_family
169option (with the
170.Fl s
171option) or the
172.Fl p Ar protocol
173option is present, show per-interface statistics on the
174.Ar interface
175for the specfied
176.Ar address_family
177or
178.Ar protocol ,
179respectively.
180.It Fl i
181Show the state of interfaces which have been auto-configured
182(interfaces statically configured into a system, but not
183located at boot time are not shown).
184If the
185.Fl a
186options is also present, multicast addresses currently in use are shown
187for each Ethernet interface and for each IP interface address.
188Multicast addresses are shown on separate lines following the interface
189address with which they are associated.
190If the
191.Fl f Ar address_family
192option (with the
193.Fl s
194option) or the
195.Fl p Ar protocol
196option is present, show per-interface statistics on all interfaces
197for the specfied
198.Ar address_family
199or
200.Ar protocol ,
201respectively.
202.It Fl L
203Show the size of the various listen queues.
204The first count shows the
205number of unaccepted connections.
206The second count shows the amount of unaccepted incomplete connections.
207The third count is the maximum number of queued connections.
208.It Fl l
209Print full IPv6 address.
210.It Fl M
211Extract values associated with the name list from the specified core
212instead of the default
213.Pa /dev/kmem .
214.It Fl m
215Show statistics recorded by the memory management routines
216(the network manages a private pool of memory buffers).
217.It Fl N
218Extract the name list from the specified system instead of the default
219.Pa /kernel .
220.It Fl n
221Show network addresses as numbers (normally
222.Nm
223interprets addresses and attempts to display them
224symbolically).
225This option may be used with any of the display formats.
226.It Fl p Ar protocol
227Show statistics about
228.Ar protocol ,
229which is either a well-known name for a protocol or an alias for it.  Some
230protocol names and aliases are listed in the file
231.Pa /etc/protocols .
232The special protocol name
233.Dq bdg
234is used to show bridging statistics.
235A null response typically means that there are no interesting numbers to
236report.
237The program will complain if
238.Ar protocol
239is unknown or if there is no statistics routine for it.
240.It Fl s
241Show per-protocol statistics.
242If this option is repeated, counters with a value of zero are suppressed.
243.It Fl r
244Show the routing tables.
245Use with
246.Fl a
247to show protocol-cloned routes.
248When
249.Fl s
250is also present, show routing statistics instead.
251When
252.Fl l
253is also present,
254.Nm
255assumes more columns are there.
256.It Fl W
257In certain displays, avoid truncating addresses even if this causes
258some fields to overflow.
259.It Fl w Ar wait
260Show network interface statistics at intervals of
261.Ar wait
262seconds.
263.El
264.Pp
265The default display, for active sockets, shows the local
266and remote addresses, send and receive queue sizes (in bytes), protocol,
267and the internal state of the protocol.
268Address formats are of the form
269.Dq host.port
270or
271.Dq network.port
272if a socket's address specifies a network but no specific host address.
273When known the host and network addresses are displayed symbolically
274according to the data bases
275.Pa /etc/hosts
276and
277.Pa /etc/networks ,
278respectively.  If a symbolic name for an address is unknown, or if
279the
280.Fl n
281option is specified, the address is printed numerically, according
282to the address family.
283For more information regarding
284the Internet
285.Dq dot format ,
286refer to
287.Xr inet 3 ) .
288Unspecified,
289or
290.Dq wildcard ,
291addresses and ports appear as
292.Dq * .
293.Pp
294The interface display provides a table of cumulative
295statistics regarding packets transferred, errors, and collisions.
296The network addresses of the interface
297and the maximum transmission unit
298.Pq Dq mtu
299are also displayed.
300.Pp
301The routing table display indicates the available routes and
302their status.  Each route consists of a destination host or network
303and a gateway to use in forwarding packets.  The flags field shows
304a collection of information about the route stored as
305binary choices.  The individual flags are discussed in more
306detail in the
307.Xr route 8
308and
309.Xr route 4
310manual pages.
311The mapping between letters and flags is:
312.Bl -column XXXX RTF_BLACKHOLE
3131	RTF_PROTO1	Protocol specific routing flag #1
3142	RTF_PROTO2	Protocol specific routing flag #2
3153	RTF_PROTO3	Protocol specific routing flag #3
316B	RTF_BLACKHOLE	Just discard pkts (during updates)
317b	RTF_BROADCAST	The route represents a broadcast address
318C	RTF_CLONING	Generate new routes on use
319c	RTF_PRCLONING	Protocol-specified generate new routes on use
320D	RTF_DYNAMIC	Created dynamically (by redirect)
321G	RTF_GATEWAY	Destination requires forwarding by intermediary
322H	RTF_HOST	Host entry (net otherwise)
323L	RTF_LLINFO	Valid protocol to link address translation
324M	RTF_MODIFIED	Modified dynamically (by redirect)
325R	RTF_REJECT	Host or net unreachable
326S	RTF_STATIC	Manually added
327U	RTF_UP	Route usable
328W	RTF_WASCLONED	Route was generated as a result of cloning
329X	RTF_XRESOLVE	External daemon translates proto to link address
330.El
331.Pp
332Direct routes are created for each
333interface attached to the local host;
334the gateway field for such entries shows the address of the outgoing interface.
335The refcnt field gives the
336current number of active uses of the route.  Connection oriented
337protocols normally hold on to a single route for the duration of
338a connection while connectionless protocols obtain a route while sending
339to the same destination.
340The use field provides a count of the number of packets
341sent using that route.  The interface entry indicates the network
342interface utilized for the route.
343.Pp
344When
345.Nm
346is invoked with the
347.Fl w
348option and a
349.Ar wait
350interval argument, it displays a running count of statistics related to
351network interfaces.
352An obsolescent version of this option used a numeric parameter
353with no option, and is currently supported for backward compatibility.
354By default, this display summarizes information for all interfaces.
355Information for a specific interface may be displayed with the
356.Fl I
357option.
358.Sh SEE ALSO
359.Xr fstat 1 ,
360.Xr nfsstat 1 ,
361.Xr sockstat 1 ,
362.Xr ps 1 ,
363.Xr inet 4 ,
364.Xr unix 4 ,
365.Xr hosts 5 ,
366.Xr networks 5 ,
367.Xr protocols 5 ,
368.Xr services 5 ,
369.Xr iostat 8 ,
370.Xr trpt 8 ,
371.Xr vmstat 8
372.Sh HISTORY
373The
374.Nm
375command appeared in
376.Bx 4.2 .
377.Pp
378IPv6 support was added by WIDE/KAME project.
379.Sh FILES
380.Bl -tag -width /dev/kmem -compact
381.It Pa /kernel
382default kernel namelist
383.It Pa /dev/kmem
384default memory file
385.El
386.Sh BUGS
387The notion of errors is ill-defined.
388