xref: /freebsd/usr.bin/netstat/netstat.1 (revision 3642298923e528d795e3a30ec165d2b469e28b40)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd September 7, 2005
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 abdhntW
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 h
121is also present, print all counters in human readable form.
122If
123.Fl t
124is also present, show the contents of watchdog timers.
125If
126.Fl W
127is also present, print interface names using a wider field size.
128.It Xo
129.Bk -words
130.Nm
131.Fl w Ar wait
132.Op Fl I Ar interface
133.Op Fl d
134.Op Fl M Ar core
135.Op Fl N Ar system
136.Ek
137.Xc
138At intervals of
139.Ar wait
140seconds,
141display the information regarding packet
142traffic on all configured network interfaces
143or a single
144.Ar interface .
145If
146.Fl d
147is also present, show the number of dropped packets.
148.It Xo
149.Bk -words
150.Nm
151.Fl s Op Fl s
152.Op Fl z
153.Op Fl f Ar protocol_family | Fl p Ar protocol
154.Op Fl M Ar core
155.Op Fl N Ar system
156.Ek
157.Xc
158Display system-wide statistics for each network protocol,
159for a particular
160.Ar protocol_family ,
161or for a single
162.Ar protocol .
163If
164.Fl s
165is repeated, counters with a value of zero are suppressed.
166If
167.Fl z
168is also present, reset statistic counters after displaying them.
169.It Xo
170.Bk -words
171.Nm
172.Fl i | I Ar interface Fl s
173.Op Fl f Ar protocol_family | Fl p Ar protocol
174.Op Fl M Ar core
175.Op Fl N Ar system
176.Ek
177.Xc
178Display per-interface statistics for each network protocol,
179for a particular
180.Ar protocol_family ,
181or for a single
182.Ar protocol .
183.It Xo
184.Bk -words
185.Nm
186.Fl m
187.Op Fl M Ar core
188.Op Fl N Ar system
189.Ek
190.Xc
191Show statistics recorded by the memory management routines
192.Pq Xr mbuf 9 .
193The network manages a private pool of memory buffers.
194.It Xo
195.Bk -words
196.Nm
197.Fl B
198.Op Fl I Ar interface
199.Ek
200.Xc
201Show statistics about
202.Xr bpf 4
203peers. This includes information like
204how many packets have been matched, dropped and recieved by the
205bpf device, also information about current buffer sizes and device
206states.
207.It Xo
208.Bk -words
209.Nm
210.Fl r
211.Op Fl AanW
212.Op Fl f Ar address_family
213.Op Fl M Ar core
214.Op Fl N Ar system
215.Ek
216.Xc
217Display the contents of all routing tables,
218or a routing table for a particular
219.Ar address_family .
220If
221.Fl A
222is also present,
223show the contents of the internal Patricia tree
224structures; used for debugging.
225If
226.Fl a
227is also present,
228show protocol-cloned routes
229(routes generated by an
230.Dv RTF_PRCLONING
231parent route);
232normally these routes are not shown.
233When
234.Fl W
235is also present,
236show the path MTU
237for each route,
238and print interface
239names with a wider
240field size.
241.It Xo
242.Bk -words
243.Nm
244.Fl rs
245.Op Fl s
246.Op Fl M Ar core
247.Op Fl N Ar system
248.Ek
249.Xc
250Display routing statistics.
251If
252.Fl s
253is repeated, counters with a value of zero are suppressed.
254.It Xo
255.Bk -words
256.Nm
257.Fl g
258.Op Fl W
259.Op Fl f Ar address_family
260.Op Fl M Ar core
261.Op Fl N Ar system
262.Ek
263.Xc
264Show information related to multicast (group address) routing.
265By default, show the IP Multicast virtual-interface and routing tables,
266and multicast group memberships.
267.It Xo
268.Bk -words
269.Nm
270.Fl gs
271.Op Fl s
272.Op Fl f Ar address_family
273.Op Fl M Ar core
274.Op Fl N Ar system
275.Ek
276.Xc
277Show multicast routing statistics.
278If
279.Fl s
280is repeated, counters with a value of zero are suppressed.
281.El
282.Pp
283Some options have the general meaning:
284.Bl -tag -width flag
285.It Fl f Ar address_family , Fl p Ar protocol
286Limit display to those records
287of the specified
288.Ar address_family
289or a single
290.Ar protocol .
291The following address families and protocols are recognized:
292.Pp
293.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
294.It Em Family
295.Em Protocols
296.It Cm inet Pq Dv AF_INET
297.Cm bdg , divert , icmp , igmp , ip , ipsec , pim, tcp , udp
298.It Cm inet6 Pq Dv AF_INET6
299.Cm bdg , icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
300.It Cm pfkey Pq Dv PF_KEY
301.Cm pfkey
302.It Cm atalk Pq Dv AF_APPLETALK
303.Cm ddp
304.It Cm netgraph , ng Pq Dv AF_NETGRAPH
305.Cm ctrl , data
306.It Cm ipx Pq Dv AF_IPX
307.Cm ipx , spx
308.\".It Cm ns Pq Dv AF_NS
309.\".Cm idp , ns_err , spp
310.\".It Cm iso Pq Dv AF_ISO
311.\".Cm clnp , cltp , esis , tp
312.It Cm unix Pq Dv AF_UNIX
313.It Cm link Pq Dv AF_LINK
314.El
315.Pp
316The program will complain if
317.Ar protocol
318is unknown or if there is no statistics routine for it.
319.It Fl M
320Extract values associated with the name list from the specified core
321instead of the default
322.Pa /dev/kmem .
323.It Fl N
324Extract the name list from the specified system instead of the default,
325which is the kernel image the system has booted from.
326.It Fl n
327Show network addresses and ports as numbers.
328Normally
329.Nm
330attempts to resolve addresses and ports,
331and display them symbolically.
332.It Fl W
333In certain displays, avoid truncating addresses even if this causes
334some fields to overflow.
335.El
336.Pp
337The default display, for active sockets, shows the local
338and remote addresses, send and receive queue sizes (in bytes), protocol,
339and the internal state of the protocol.
340Address formats are of the form
341.Dq host.port
342or
343.Dq network.port
344if a socket's address specifies a network but no specific host address.
345When known, the host and network addresses are displayed symbolically
346according to the databases
347.Xr hosts 5
348and
349.Xr networks 5 ,
350respectively.
351If a symbolic name for an address is unknown, or if
352the
353.Fl n
354option is specified, the address is printed numerically, according
355to the address family.
356For more information regarding
357the Internet IPv4
358.Dq dot format ,
359refer to
360.Xr inet 3 .
361Unspecified,
362or
363.Dq wildcard ,
364addresses and ports appear as
365.Dq Li * .
366.Pp
367The interface display provides a table of cumulative
368statistics regarding packets transferred, errors, and collisions.
369The network addresses of the interface
370and the maximum transmission unit
371.Pq Dq mtu
372are also displayed.
373.Pp
374The routing table display indicates the available routes and their status.
375Each route consists of a destination host or network, and a gateway to use
376in forwarding packets.
377The flags field shows a collection of information about the route stored
378as binary choices.
379The individual flags are discussed in more detail in the
380.Xr route 8
381and
382.Xr route 4
383manual pages.
384The mapping between letters and flags is:
385.Bl -column ".Li W" ".Dv RTF_WASCLONED"
386.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
387.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
388.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
389.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
390.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
391.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
392.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
393.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
394.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
395.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
396.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
397.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
398.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
399.It Li S Ta Dv RTF_STATIC Ta "Manually added"
400.It Li U Ta Dv RTF_UP Ta "Route usable"
401.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
402.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
403.El
404.Pp
405Direct routes are created for each
406interface attached to the local host;
407the gateway field for such entries shows the address of the outgoing interface.
408The refcnt field gives the
409current number of active uses of the route.
410Connection oriented
411protocols normally hold on to a single route for the duration of
412a connection while connectionless protocols obtain a route while sending
413to the same destination.
414The use field provides a count of the number of packets
415sent using that route.
416The interface entry indicates the network interface utilized for the route.
417.Pp
418When
419.Nm
420is invoked with the
421.Fl w
422option and a
423.Ar wait
424interval argument, it displays a running count of statistics related to
425network interfaces.
426An obsolescent version of this option used a numeric parameter
427with no option, and is currently supported for backward compatibility.
428By default, this display summarizes information for all interfaces.
429Information for a specific interface may be displayed with the
430.Fl I
431option.
432.Sh SEE ALSO
433.Xr fstat 1 ,
434.Xr nfsstat 1 ,
435.Xr ps 1 ,
436.Xr sockstat 1 ,
437.Xr inet 4 ,
438.Xr route 4 ,
439.Xr unix 4 ,
440.Xr hosts 5 ,
441.Xr networks 5 ,
442.Xr protocols 5 ,
443.Xr services 5 ,
444.Xr iostat 8 ,
445.Xr route 8 ,
446.Xr trpt 8 ,
447.Xr vmstat 8 ,
448.Xr mbuf 9
449.Sh HISTORY
450The
451.Nm
452command appeared in
453.Bx 4.2 .
454.Pp
455IPv6 support was added by WIDE/KAME project.
456.Sh BUGS
457The notion of errors is ill-defined.
458