xref: /freebsd/usr.bin/netstat/netstat.1 (revision 09c817ba36db7c3a4ff5e25ac55816ca181a403d)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd February 15, 2009
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 AaLnSWx
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.
88If
89.Fl x
90is present display full socket buffer statistics for each internet socket.
91.It Xo
92.Bk -words
93.Nm
94.Fl i | I Ar interface
95.Op Fl abdhntW
96.Op Fl f Ar address_family
97.Op Fl M Ar core
98.Op Fl N Ar system
99.Ek
100.Xc
101Show the state of all network interfaces or a single
102.Ar interface
103which have been auto-configured
104(interfaces statically configured into a system, but not
105located at boot time are not shown).
106An asterisk
107.Pq Dq Li *
108after an interface name indicates that the interface is
109.Dq down .
110If
111.Fl a
112is also present, multicast addresses currently in use are shown
113for each Ethernet interface and for each IP interface address.
114Multicast addresses are shown on separate lines following the interface
115address with which they are associated.
116If
117.Fl b
118is also present, show the number of bytes in and out.
119If
120.Fl d
121is also present, show the number of dropped packets.
122If
123.Fl h
124is also present, print all counters in human readable form.
125If
126.Fl t
127is also present, show the contents of watchdog timers.
128If
129.Fl W
130is also present, print interface names using a wider field size.
131.It Xo
132.Bk -words
133.Nm
134.Fl w Ar wait
135.Op Fl I Ar interface
136.Op Fl d
137.Op Fl M Ar core
138.Op Fl N Ar system
139.Ek
140.Xc
141At intervals of
142.Ar wait
143seconds,
144display the information regarding packet
145traffic on all configured network interfaces
146or a single
147.Ar interface .
148If
149.Fl d
150is also present, show the number of dropped packets.
151.It Xo
152.Bk -words
153.Nm
154.Fl s Op Fl s
155.Op Fl z
156.Op Fl f Ar protocol_family | Fl p Ar protocol
157.Op Fl M Ar core
158.Op Fl N Ar system
159.Ek
160.Xc
161Display system-wide statistics for each network protocol,
162for a particular
163.Ar protocol_family ,
164or for a single
165.Ar protocol .
166If
167.Fl s
168is repeated, counters with a value of zero are suppressed.
169If
170.Fl z
171is also present, reset statistic counters after displaying them.
172.It Xo
173.Bk -words
174.Nm
175.Fl i | I Ar interface Fl s
176.Op Fl f Ar protocol_family | Fl p Ar protocol
177.Op Fl M Ar core
178.Op Fl N Ar system
179.Ek
180.Xc
181Display per-interface statistics for each network protocol,
182for a particular
183.Ar protocol_family ,
184or for a single
185.Ar protocol .
186.It Xo
187.Bk -words
188.Nm
189.Fl m
190.Op Fl M Ar core
191.Op Fl N Ar system
192.Ek
193.Xc
194Show statistics recorded by the memory management routines
195.Pq Xr mbuf 9 .
196The network manages a private pool of memory buffers.
197.It Xo
198.Bk -words
199.Nm
200.Fl B
201.Op Fl z
202.Op Fl I Ar interface
203.Ek
204.Xc
205Show statistics about
206.Xr bpf 4
207peers.
208This includes information like
209how many packets have been matched, dropped and received by the
210bpf device, also information about current buffer sizes and device
211states.
212.It Xo
213.Bk -words
214.Nm
215.Fl r
216.Op Fl AanW
217.Op Fl f Ar address_family
218.Op Fl M Ar core
219.Op Fl N Ar system
220.Ek
221.Xc
222Display the contents of all routing tables,
223or a routing table for a particular
224.Ar address_family .
225If
226.Fl A
227is also present,
228show the contents of the internal Patricia tree
229structures; used for debugging.
230If
231.Fl a
232is also present,
233show protocol-cloned routes
234(routes generated by an
235.Dv RTF_PRCLONING
236parent route);
237normally these routes are not shown.
238When
239.Fl W
240is also present,
241show the path MTU
242for each route,
243and print interface
244names with a wider
245field size.
246.It Xo
247.Bk -words
248.Nm
249.Fl rs
250.Op Fl s
251.Op Fl M Ar core
252.Op Fl N Ar system
253.Ek
254.Xc
255Display routing statistics.
256If
257.Fl s
258is repeated, counters with a value of zero are suppressed.
259.It Xo
260.Bk -words
261.Nm
262.Fl g
263.Op Fl W
264.Op Fl f Ar address_family
265.Op Fl M Ar core
266.Op Fl N Ar system
267.Ek
268.Xc
269Display the contents of the multicast virtual interface tables,
270and multicast forwarding caches.
271Entries in these tables will appear only when the kernel is
272actively forwarding multicast sessions.
273This option is applicable only to the
274.Cm inet
275and
276.Cm inet6
277address families.
278.It Xo
279.Bk -words
280.Nm
281.Fl gs
282.Op Fl s
283.Op Fl f Ar address_family
284.Op Fl M Ar core
285.Op Fl N Ar system
286.Ek
287.Xc
288Show multicast routing statistics.
289If
290.Fl s
291is repeated, counters with a value of zero are suppressed.
292.El
293.Pp
294Some options have the general meaning:
295.Bl -tag -width flag
296.It Fl f Ar address_family , Fl p Ar protocol
297Limit display to those records
298of the specified
299.Ar address_family
300or a single
301.Ar protocol .
302The following address families and protocols are recognized:
303.Pp
304.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
305.It Em Family
306.Em Protocols
307.It Cm inet Pq Dv AF_INET
308.Cm divert , icmp , igmp , ip , ipsec , pim, sctp , tcp , udp
309.It Cm inet6 Pq Dv AF_INET6
310.Cm icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
311.It Cm pfkey Pq Dv PF_KEY
312.Cm pfkey
313.It Cm atalk Pq Dv AF_APPLETALK
314.Cm ddp
315.It Cm netgraph , ng Pq Dv AF_NETGRAPH
316.Cm ctrl , data
317.It Cm ipx Pq Dv AF_IPX
318.Cm ipx , spx
319.\".It Cm ns Pq Dv AF_NS
320.\".Cm idp , ns_err , spp
321.\".It Cm iso Pq Dv AF_ISO
322.\".Cm clnp , cltp , esis , tp
323.It Cm unix Pq Dv AF_UNIX
324.It Cm link Pq Dv AF_LINK
325.El
326.Pp
327The program will complain if
328.Ar protocol
329is unknown or if there is no statistics routine for it.
330.It Fl M
331Extract values associated with the name list from the specified core
332instead of the default
333.Pa /dev/kmem .
334.It Fl N
335Extract the name list from the specified system instead of the default,
336which is the kernel image the system has booted from.
337.It Fl n
338Show network addresses and ports as numbers.
339Normally
340.Nm
341attempts to resolve addresses and ports,
342and display them symbolically.
343.It Fl W
344In certain displays, avoid truncating addresses even if this causes
345some fields to overflow.
346.El
347.Pp
348The default display, for active sockets, shows the local
349and remote addresses, send and receive queue sizes (in bytes), protocol,
350and the internal state of the protocol.
351Address formats are of the form
352.Dq host.port
353or
354.Dq network.port
355if a socket's address specifies a network but no specific host address.
356When known, the host and network addresses are displayed symbolically
357according to the databases
358.Xr hosts 5
359and
360.Xr networks 5 ,
361respectively.
362If a symbolic name for an address is unknown, or if
363the
364.Fl n
365option is specified, the address is printed numerically, according
366to the address family.
367For more information regarding
368the Internet IPv4
369.Dq dot format ,
370refer to
371.Xr inet 3 .
372Unspecified,
373or
374.Dq wildcard ,
375addresses and ports appear as
376.Dq Li * .
377.Pp
378The interface display provides a table of cumulative
379statistics regarding packets transferred, errors, and collisions.
380The network addresses of the interface
381and the maximum transmission unit
382.Pq Dq mtu
383are also displayed.
384.Pp
385The routing table display indicates the available routes and their status.
386Each route consists of a destination host or network, and a gateway to use
387in forwarding packets.
388The flags field shows a collection of information about the route stored
389as binary choices.
390The individual flags are discussed in more detail in the
391.Xr route 8
392and
393.Xr route 4
394manual pages.
395The mapping between letters and flags is:
396.Bl -column ".Li W" ".Dv RTF_WASCLONED"
397.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
398.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
399.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
400.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
401.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
402.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
403.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
404.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
405.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
406.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
407.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
408.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
409.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
410.It Li S Ta Dv RTF_STATIC Ta "Manually added"
411.It Li U Ta Dv RTF_UP Ta "Route usable"
412.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
413.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
414.El
415.Pp
416Direct routes are created for each
417interface attached to the local host;
418the gateway field for such entries shows the address of the outgoing interface.
419The refcnt field gives the
420current number of active uses of the route.
421Connection oriented
422protocols normally hold on to a single route for the duration of
423a connection while connectionless protocols obtain a route while sending
424to the same destination.
425The use field provides a count of the number of packets
426sent using that route.
427The interface entry indicates the network interface utilized for the route.
428.Pp
429When
430.Nm
431is invoked with the
432.Fl w
433option and a
434.Ar wait
435interval argument, it displays a running count of statistics related to
436network interfaces.
437An obsolescent version of this option used a numeric parameter
438with no option, and is currently supported for backward compatibility.
439By default, this display summarizes information for all interfaces.
440Information for a specific interface may be displayed with the
441.Fl I
442option.
443.Pp
444The
445.Xr bpf 4
446flags displayed when
447.Nm
448is invoked with the
449.Fl B
450option represent the underlying parameters of the bpf peer.
451Each flag is
452represented as a single lower case letter.
453The mapping between the letters and flags in order of appearance are:
454.Bl -column ".Li i"
455.It Li p Ta Set if listening promiscuously
456.It Li i Ta Dv BIOCIMMEDIATE No has been set on the device
457.It Li f Ta Dv BIOCGHDRCMPLT No status: source link addresses are being
458filled automatically
459.It Li s Ta Dv BIOCGSEESENT No status: see packets originating locally and
460remotely on the interface.
461.It Li a Ta Packet reception generates a signal
462.It Li l Ta Dv BIOCLOCK No status: descriptor has been locked
463.El
464.Pp
465For more information about these flags, please refer to
466.Xr bpf 4 .
467.Pp
468The
469.Fl x
470flag causes
471.Nm
472to output all the information recorded about data
473stored in the socket buffers.
474The fields are:
475.Bl -column ".Li R-MBUF"
476.It Li R-MBUF Ta Number of mbufs in the receive queue.
477.It Li S-MBUF Ta Number of mbufs in the send queue.
478.It Li R-CLUS Ta Number of clusters, of any type, in the receive
479queue.
480.It Li S-CLUS Ta Number of clusters, of any type, in the send queue.
481.It Li R-HIWA Ta Receive buffer high water mark, in bytes.
482.It Li S-HIWA Ta Send buffer high water mark, in bytes.
483.It Li R-LOWA Ta Receive buffer low water mark, in bytes.
484.It Li S-LOWA Ta Send buffer low water mark, in bytes.
485.It Li R-BCNT Ta Receive buffer byte count.
486.It Li S-BCNT Ta Send buffer byte count.
487.It Li R-BMAX Ta Maximum bytes that can be used in the receive buffer.
488.It Li S-BMAX Ta Maximum bytes that can be used in the send buffer.
489.El
490.Sh SEE ALSO
491.Xr fstat 1 ,
492.Xr nfsstat 1 ,
493.Xr ps 1 ,
494.Xr sockstat 1 ,
495.Xr bpf 4 ,
496.Xr inet 4 ,
497.Xr route 4 ,
498.Xr unix 4 ,
499.Xr hosts 5 ,
500.Xr networks 5 ,
501.Xr protocols 5 ,
502.Xr services 5 ,
503.Xr iostat 8 ,
504.Xr route 8 ,
505.Xr trpt 8 ,
506.Xr vmstat 8 ,
507.Xr mbuf 9
508.Sh HISTORY
509The
510.Nm
511command appeared in
512.Bx 4.2 .
513.Pp
514IPv6 support was added by WIDE/KAME project.
515.Sh BUGS
516The notion of errors is ill-defined.
517