xref: /freebsd/usr.bin/netstat/netstat.1 (revision eb6d21b4ca6d668cf89afd99eef7baeafa712197)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd July 9, 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 socket buffer and tcp timer statistics for each internet socket.
91.It Xo
92.Bk -words
93.Nm
94.Fl i | I Ar interface
95.Op Fl abdhnW
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 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 z
199.Op Fl I Ar interface
200.Ek
201.Xc
202Show statistics about
203.Xr bpf 4
204peers.
205This includes information like
206how many packets have been matched, dropped and received by the
207bpf device, also information about current buffer sizes and device
208states.
209.It Xo
210.Bk -words
211.Nm
212.Fl r
213.Op Fl AanW
214.Op Fl f Ar address_family
215.Op Fl M Ar core
216.Op Fl N Ar system
217.Ek
218.Xc
219Display the contents of all routing tables,
220or a routing table for a particular
221.Ar address_family .
222If
223.Fl A
224is also present,
225show the contents of the internal Patricia tree
226structures; used for debugging.
227If
228.Fl a
229is also present,
230show protocol-cloned routes
231(routes generated by an
232.Dv RTF_PRCLONING
233parent route);
234normally these routes are not shown.
235When
236.Fl W
237is also present,
238show the path MTU
239for each route,
240and print interface
241names with a wider
242field size.
243.It Xo
244.Bk -words
245.Nm
246.Fl rs
247.Op Fl s
248.Op Fl M Ar core
249.Op Fl N Ar system
250.Ek
251.Xc
252Display routing statistics.
253If
254.Fl s
255is repeated, counters with a value of zero are suppressed.
256.It Xo
257.Bk -words
258.Nm
259.Fl g
260.Op Fl W
261.Op Fl f Ar address_family
262.Op Fl M Ar core
263.Op Fl N Ar system
264.Ek
265.Xc
266Display the contents of the multicast virtual interface tables,
267and multicast forwarding caches.
268Entries in these tables will appear only when the kernel is
269actively forwarding multicast sessions.
270This option is applicable only to the
271.Cm inet
272and
273.Cm inet6
274address families.
275.It Xo
276.Bk -words
277.Nm
278.Fl gs
279.Op Fl s
280.Op Fl f Ar address_family
281.Op Fl M Ar core
282.Op Fl N Ar system
283.Ek
284.Xc
285Show multicast routing statistics.
286If
287.Fl s
288is repeated, counters with a value of zero are suppressed.
289.El
290.Pp
291Some options have the general meaning:
292.Bl -tag -width flag
293.It Fl f Ar address_family , Fl p Ar protocol
294Limit display to those records
295of the specified
296.Ar address_family
297or a single
298.Ar protocol .
299The following address families and protocols are recognized:
300.Pp
301.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
302.It Em Family
303.Em Protocols
304.It Cm inet Pq Dv AF_INET
305.Cm divert , icmp , igmp , ip , ipsec , pim, sctp , tcp , udp
306.It Cm inet6 Pq Dv AF_INET6
307.Cm icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
308.It Cm pfkey Pq Dv PF_KEY
309.Cm pfkey
310.It Cm atalk Pq Dv AF_APPLETALK
311.Cm ddp
312.It Cm netgraph , ng Pq Dv AF_NETGRAPH
313.Cm ctrl , data
314.It Cm ipx Pq Dv AF_IPX
315.Cm ipx , spx
316.\".It Cm ns Pq Dv AF_NS
317.\".Cm idp , ns_err , spp
318.\".It Cm iso Pq Dv AF_ISO
319.\".Cm clnp , cltp , esis , tp
320.It Cm unix Pq Dv AF_UNIX
321.It Cm link Pq Dv AF_LINK
322.El
323.Pp
324The program will complain if
325.Ar protocol
326is unknown or if there is no statistics routine for it.
327.It Fl M
328Extract values associated with the name list from the specified core
329instead of the default
330.Pa /dev/kmem .
331.It Fl N
332Extract the name list from the specified system instead of the default,
333which is the kernel image the system has booted from.
334.It Fl n
335Show network addresses and ports as numbers.
336Normally
337.Nm
338attempts to resolve addresses and ports,
339and display them symbolically.
340.It Fl W
341In certain displays, avoid truncating addresses even if this causes
342some fields to overflow.
343.El
344.Pp
345The default display, for active sockets, shows the local
346and remote addresses, send and receive queue sizes (in bytes), protocol,
347and the internal state of the protocol.
348Address formats are of the form
349.Dq host.port
350or
351.Dq network.port
352if a socket's address specifies a network but no specific host address.
353When known, the host and network addresses are displayed symbolically
354according to the databases
355.Xr hosts 5
356and
357.Xr networks 5 ,
358respectively.
359If a symbolic name for an address is unknown, or if
360the
361.Fl n
362option is specified, the address is printed numerically, according
363to the address family.
364For more information regarding
365the Internet IPv4
366.Dq dot format ,
367refer to
368.Xr inet 3 .
369Unspecified,
370or
371.Dq wildcard ,
372addresses and ports appear as
373.Dq Li * .
374.Pp
375The interface display provides a table of cumulative
376statistics regarding packets transferred, errors, and collisions.
377The network addresses of the interface
378and the maximum transmission unit
379.Pq Dq mtu
380are also displayed.
381.Pp
382The routing table display indicates the available routes and their status.
383Each route consists of a destination host or network, and a gateway to use
384in forwarding packets.
385The flags field shows a collection of information about the route stored
386as binary choices.
387The individual flags are discussed in more detail in the
388.Xr route 8
389and
390.Xr route 4
391manual pages.
392The mapping between letters and flags is:
393.Bl -column ".Li W" ".Dv RTF_WASCLONED"
394.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
395.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
396.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
397.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
398.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
399.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
400.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
401.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
402.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
403.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
404.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
405.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
406.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
407.It Li S Ta Dv RTF_STATIC Ta "Manually added"
408.It Li U Ta Dv RTF_UP Ta "Route usable"
409.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
410.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
411.El
412.Pp
413Direct routes are created for each
414interface attached to the local host;
415the gateway field for such entries shows the address of the outgoing interface.
416The refcnt field gives the
417current number of active uses of the route.
418Connection oriented
419protocols normally hold on to a single route for the duration of
420a connection while connectionless protocols obtain a route while sending
421to the same destination.
422The use field provides a count of the number of packets
423sent using that route.
424The interface entry indicates the network interface utilized for the route.
425.Pp
426When
427.Nm
428is invoked with the
429.Fl w
430option and a
431.Ar wait
432interval argument, it displays a running count of statistics related to
433network interfaces.
434An obsolescent version of this option used a numeric parameter
435with no option, and is currently supported for backward compatibility.
436By default, this display summarizes information for all interfaces.
437Information for a specific interface may be displayed with the
438.Fl I
439option.
440.Pp
441The
442.Xr bpf 4
443flags displayed when
444.Nm
445is invoked with the
446.Fl B
447option represent the underlying parameters of the bpf peer.
448Each flag is
449represented as a single lower case letter.
450The mapping between the letters and flags in order of appearance are:
451.Bl -column ".Li i"
452.It Li p Ta Set if listening promiscuously
453.It Li i Ta Dv BIOCIMMEDIATE No has been set on the device
454.It Li f Ta Dv BIOCGHDRCMPLT No status: source link addresses are being
455filled automatically
456.It Li s Ta Dv BIOCGSEESENT No status: see packets originating locally and
457remotely on the interface.
458.It Li a Ta Packet reception generates a signal
459.It Li l Ta Dv BIOCLOCK No status: descriptor has been locked
460.El
461.Pp
462For more information about these flags, please refer to
463.Xr bpf 4 .
464.Pp
465The
466.Fl x
467flag causes
468.Nm
469to output all the information recorded about data
470stored in the socket buffers.
471The fields are:
472.Bl -column ".Li R-MBUF"
473.It Li R-MBUF Ta Number of mbufs in the receive queue.
474.It Li S-MBUF Ta Number of mbufs in the send queue.
475.It Li R-CLUS Ta Number of clusters, of any type, in the receive
476queue.
477.It Li S-CLUS Ta Number of clusters, of any type, in the send queue.
478.It Li R-HIWA Ta Receive buffer high water mark, in bytes.
479.It Li S-HIWA Ta Send buffer high water mark, in bytes.
480.It Li R-LOWA Ta Receive buffer low water mark, in bytes.
481.It Li S-LOWA Ta Send buffer low water mark, in bytes.
482.It Li R-BCNT Ta Receive buffer byte count.
483.It Li S-BCNT Ta Send buffer byte count.
484.It Li R-BMAX Ta Maximum bytes that can be used in the receive buffer.
485.It Li S-BMAX Ta Maximum bytes that can be used in the send buffer.
486.El
487.Sh SEE ALSO
488.Xr fstat 1 ,
489.Xr nfsstat 1 ,
490.Xr procstat 1 ,
491.Xr ps 1 ,
492.Xr sockstat 1 ,
493.Xr bpf 4 ,
494.Xr inet 4 ,
495.Xr route 4 ,
496.Xr unix 4 ,
497.Xr hosts 5 ,
498.Xr networks 5 ,
499.Xr protocols 5 ,
500.Xr services 5 ,
501.Xr iostat 8 ,
502.Xr route 8 ,
503.Xr trpt 8 ,
504.Xr vmstat 8 ,
505.Xr mbuf 9
506.Sh HISTORY
507The
508.Nm
509command appeared in
510.Bx 4.2 .
511.Pp
512IPv6 support was added by WIDE/KAME project.
513.Sh BUGS
514The notion of errors is ill-defined.
515