xref: /freebsd/usr.bin/netstat/netstat.1 (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd June 15, 2001
36.Dt NETSTAT 1
37.Os
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 | Fl p Ar protocol
45.Op Fl M Ar core
46.Op Fl N Ar system
47.Nm
48.Op Fl gilnsS
49.Op Fl f Ar address_family
50.Op Fl M Ar core
51.Op Fl N Ar system
52.Nm
53.Fl i | I Ar interface
54.Op Fl w Ar wait
55.Op Fl abdgt
56.Op Fl M Ar core
57.Op Fl N Ar system
58.Nm
59.Fl s Op Fl s
60.Op Fl z
61.Op Fl f Ar address_family | Fl p Ar protocol
62.Op Fl M Ar core
63.Op Fl N Ar system
64.Nm
65.Fl i | I Ar interface Fl s
66.Op Fl f Ar address_family | Fl p Ar protocol
67.Op Fl M Ar core
68.Op Fl N Ar system
69.Nm
70.Fl m
71.Op Fl M Ar core
72.Op Fl N Ar system
73.Nm
74.Fl r
75.Op Fl Aaln
76.Op Fl f Ar address_family
77.Op Fl M Ar core
78.Op Fl N Ar system
79.Nm
80.Fl rs
81.Op Fl s
82.Op Fl M Ar core
83.Op Fl N Ar system
84.Sh DESCRIPTION
85The
86.Nm
87command symbolically displays the contents of various network-related
88data structures.
89There are a number of output formats,
90depending on the options for the information presented.
91The first form of the command displays a list of active sockets for
92each protocol.
93The second form presents the contents of one of the other network
94data structures according to the option selected.
95Using the third form, with a
96.Ar wait
97interval specified,
98.Nm
99will continuously display the information regarding packet
100traffic on the configured network interfaces.
101The fourth form displays statistics for
102the specified protocol or address family.
103The fifth form displays per-interface statistics for
104the specified protocol or address family.
105The sixth form displays
106.Xr mbuf 9
107statistics.
108The seventh form displays routing table for the specified address family.
109The eighth form displays routing statistics.
110.Pp
111The options have the following meaning:
112.Bl -tag -width flag
113.It Fl A
114With the default display,
115show the address of any protocol control blocks associated with sockets; used
116for debugging.
117.It Fl a
118With the default display,
119show the state of all sockets; normally sockets used by
120server processes are not shown.
121With the routing table display (option
122.Fl r ,
123as described below), show protocol-cloned routes (routes
124generated by a
125.Dv RTF_PRCLONING
126parent route); normally these routes are
127not shown.
128.It Fl b
129With the interface display (option
130.Fl i ,
131as described below),
132show the number of bytes in and out.
133.It Fl d
134With either interface display (option
135.Fl i
136or an interval, as described below),
137show the number of dropped packets.
138.It Fl f Ar address_family
139Limit statistics or address control block reports to those
140of the specified
141.Ar address family  .
142The following address families
143are recognized:
144.Ar inet  ,
145for
146.Dv AF_INET  ,
147.Ar inet6  ,
148for
149.Dv AF_INET6  ,
150.Ar ipx ,
151for
152.Dv AF_IPX  ,
153.Ar atalk ,
154for
155.Dv AF_APPLETALK (ddp)  ,
156.Ar netgraph
157or
158.Ar ng
159for
160.Dv AF_NETGRAPH ,
161.\".Ar ns ,
162.\"for
163.\".Dv AF_NS  ,
164.\".Ar iso ,
165.\"for
166.\".Dv AF_ISO ,
167and
168.Ar unix  ,
169for
170.Dv AF_UNIX  .
171.It Fl g
172Show information related to multicast (group address) routing.
173By default, show the IP Multicast virtual-interface and routing tables.
174If the
175.Fl s
176option is also present, show multicast routing statistics.
177.It Fl I Ar interface
178Show information about the specified interface;
179used with a
180.Ar wait
181interval as described below.
182If the
183.Fl s
184option is present, show per-interface protocol statistics on the
185.Ar interface
186for the specified
187.Ar address_family
188or
189.Ar protocol ,
190or for all protocol families.
191.It Fl i
192Show the state of interfaces which have been auto-configured
193(interfaces statically configured into a system, but not
194located at boot time are not shown).
195If the
196.Fl a
197options is also present, multicast addresses currently in use are shown
198for each Ethernet interface and for each IP interface address.
199Multicast addresses are shown on separate lines following the interface
200address with which they are associated.
201If the
202.Fl s
203option is present, show per-interface statistics on all interfaces
204for the specified
205.Ar address_family
206or
207.Ar protocol ,
208or for all protocol families.
209.It Fl L
210Show the size of the various listen queues.
211The first count shows the
212number of unaccepted connections.
213The second count shows the amount of unaccepted incomplete connections.
214The third count is the maximum number of queued connections.
215.It Fl l
216Print full IPv6 address.
217.It Fl M
218Extract values associated with the name list from the specified core
219instead of the default
220.Pa /dev/kmem .
221.It Fl m
222Show statistics recorded by the memory management routines
223(the network manages a private pool of memory buffers).
224.It Fl N
225Extract the name list from the specified system instead of the default
226.Pa /kernel .
227.It Fl n
228Show network addresses and ports as numbers (normally
229.Nm
230interprets addresses and ports and attempts to display them
231symbolically).
232This option may be used with any of the display formats.
233.It Fl p Ar protocol
234Show statistics about
235.Ar protocol ,
236which is either a well-known name for a protocol or an alias for it.  Some
237protocol names and aliases are listed in the file
238.Pa /etc/protocols .
239The special protocol name
240.Dq bdg
241is used to show bridging statistics.
242A null response typically means that there are no interesting numbers to
243report.
244The program will complain if
245.Ar protocol
246is unknown or if there is no statistics routine for it.
247.It Fl r
248Show the routing tables.
249Use with
250.Fl a
251to show protocol-cloned routes.
252When
253.Fl s
254is also present, show routing statistics instead.
255When
256.Fl l
257is also present,
258.Nm
259assumes more columns are there and the maximum transmission unit
260.Pq Dq mtu
261are also displayed.
262.It Fl S
263Show network addresses as numbers (as with
264.Fl n )
265but show ports symbolically).
266.It Fl s
267Show per-protocol statistics.
268If this option is repeated, counters with a value of zero are suppressed.
269.It Fl W
270In certain displays, avoid truncating addresses even if this causes
271some fields to overflow.
272.It Fl w Ar wait
273Show network interface statistics at intervals of
274.Ar wait
275seconds.
276.It Fl z
277Reset statistics.
278.El
279.Pp
280The default display, for active sockets, shows the local
281and remote addresses, send and receive queue sizes (in bytes), protocol,
282and the internal state of the protocol.
283Address formats are of the form
284.Dq host.port
285or
286.Dq network.port
287if a socket's address specifies a network but no specific host address.
288When known the host and network addresses are displayed symbolically
289according to the data bases
290.Pa /etc/hosts
291and
292.Pa /etc/networks ,
293respectively.  If a symbolic name for an address is unknown, or if
294the
295.Fl n
296option is specified, the address is printed numerically, according
297to the address family.
298For more information regarding
299the Internet
300.Dq dot format ,
301refer to
302.Xr inet 3 ) .
303Unspecified,
304or
305.Dq wildcard ,
306addresses and ports appear as
307.Dq * .
308.Pp
309The interface display provides a table of cumulative
310statistics regarding packets transferred, errors, and collisions.
311The network addresses of the interface
312and the maximum transmission unit
313.Pq Dq mtu
314are also displayed.
315.Pp
316The routing table display indicates the available routes and
317their status.  Each route consists of a destination host or network
318and a gateway to use in forwarding packets.  The flags field shows
319a collection of information about the route stored as
320binary choices.  The individual flags are discussed in more
321detail in the
322.Xr route 8
323and
324.Xr route 4
325manual pages.
326The mapping between letters and flags is:
327.Bl -column XXXX RTF_BLACKHOLE
3281	RTF_PROTO1	Protocol specific routing flag #1
3292	RTF_PROTO2	Protocol specific routing flag #2
3303	RTF_PROTO3	Protocol specific routing flag #3
331B	RTF_BLACKHOLE	Just discard pkts (during updates)
332b	RTF_BROADCAST	The route represents a broadcast address
333C	RTF_CLONING	Generate new routes on use
334c	RTF_PRCLONING	Protocol-specified generate new routes on use
335D	RTF_DYNAMIC	Created dynamically (by redirect)
336G	RTF_GATEWAY	Destination requires forwarding by intermediary
337H	RTF_HOST	Host entry (net otherwise)
338L	RTF_LLINFO	Valid protocol to link address translation
339M	RTF_MODIFIED	Modified dynamically (by redirect)
340R	RTF_REJECT	Host or net unreachable
341S	RTF_STATIC	Manually added
342U	RTF_UP	Route usable
343W	RTF_WASCLONED	Route was generated as a result of cloning
344X	RTF_XRESOLVE	External daemon translates proto to link address
345.El
346.Pp
347Direct routes are created for each
348interface attached to the local host;
349the gateway field for such entries shows the address of the outgoing interface.
350The refcnt field gives the
351current number of active uses of the route.  Connection oriented
352protocols normally hold on to a single route for the duration of
353a connection while connectionless protocols obtain a route while sending
354to the same destination.
355The use field provides a count of the number of packets
356sent using that route.  The interface entry indicates the network
357interface utilized for the route.
358.Pp
359When
360.Nm
361is invoked with the
362.Fl w
363option and a
364.Ar wait
365interval argument, it displays a running count of statistics related to
366network interfaces.
367An obsolescent version of this option used a numeric parameter
368with no option, and is currently supported for backward compatibility.
369By default, this display summarizes information for all interfaces.
370Information for a specific interface may be displayed with the
371.Fl I
372option.
373.Sh SEE ALSO
374.Xr fstat 1 ,
375.Xr nfsstat 1 ,
376.Xr ps 1 ,
377.Xr sockstat 1 ,
378.Xr inet 4 ,
379.Xr unix 4 ,
380.Xr hosts 5 ,
381.Xr networks 5 ,
382.Xr protocols 5 ,
383.Xr services 5 ,
384.Xr iostat 8 ,
385.Xr trpt 8 ,
386.Xr vmstat 8
387.Sh HISTORY
388The
389.Nm
390command appeared in
391.Bx 4.2 .
392.Pp
393IPv6 support was added by WIDE/KAME project.
394.Sh FILES
395.Bl -tag -width /dev/kmem -compact
396.It Pa /kernel
397default kernel namelist
398.It Pa /dev/kmem
399default memory file
400.El
401.Sh BUGS
402The notion of errors is ill-defined.
403