xref: /freebsd/usr.bin/netstat/netstat.1 (revision 721351876cd4d3a8a700f62d2061331fa951a488)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd June 10, 2007
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 I Ar interface
202.Ek
203.Xc
204Show statistics about
205.Xr bpf 4
206peers.
207This includes information like
208how many packets have been matched, dropped and received by the
209bpf device, also information about current buffer sizes and device
210states.
211.It Xo
212.Bk -words
213.Nm
214.Fl r
215.Op Fl AanW
216.Op Fl f Ar address_family
217.Op Fl M Ar core
218.Op Fl N Ar system
219.Ek
220.Xc
221Display the contents of all routing tables,
222or a routing table for a particular
223.Ar address_family .
224If
225.Fl A
226is also present,
227show the contents of the internal Patricia tree
228structures; used for debugging.
229If
230.Fl a
231is also present,
232show protocol-cloned routes
233(routes generated by an
234.Dv RTF_PRCLONING
235parent route);
236normally these routes are not shown.
237When
238.Fl W
239is also present,
240show the path MTU
241for each route,
242and print interface
243names with a wider
244field size.
245.It Xo
246.Bk -words
247.Nm
248.Fl rs
249.Op Fl s
250.Op Fl M Ar core
251.Op Fl N Ar system
252.Ek
253.Xc
254Display routing statistics.
255If
256.Fl s
257is repeated, counters with a value of zero are suppressed.
258.It Xo
259.Bk -words
260.Nm
261.Fl g
262.Op Fl W
263.Op Fl f Ar address_family
264.Op Fl M Ar core
265.Op Fl N Ar system
266.Ek
267.Xc
268Show information related to multicast (group address) routing.
269By default, show the IP Multicast virtual-interface and routing tables,
270and multicast group memberships.
271.It Xo
272.Bk -words
273.Nm
274.Fl gs
275.Op Fl s
276.Op Fl f Ar address_family
277.Op Fl M Ar core
278.Op Fl N Ar system
279.Ek
280.Xc
281Show multicast routing statistics.
282If
283.Fl s
284is repeated, counters with a value of zero are suppressed.
285.El
286.Pp
287Some options have the general meaning:
288.Bl -tag -width flag
289.It Fl f Ar address_family , Fl p Ar protocol
290Limit display to those records
291of the specified
292.Ar address_family
293or a single
294.Ar protocol .
295The following address families and protocols are recognized:
296.Pp
297.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
298.It Em Family
299.Em Protocols
300.It Cm inet Pq Dv AF_INET
301.Cm divert , icmp , igmp , ip , ipsec , pim, sctp , tcp , udp
302.It Cm inet6 Pq Dv AF_INET6
303.Cm icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
304.It Cm pfkey Pq Dv PF_KEY
305.Cm pfkey
306.It Cm atalk Pq Dv AF_APPLETALK
307.Cm ddp
308.It Cm netgraph , ng Pq Dv AF_NETGRAPH
309.Cm ctrl , data
310.It Cm ipx Pq Dv AF_IPX
311.Cm ipx , spx
312.\".It Cm ns Pq Dv AF_NS
313.\".Cm idp , ns_err , spp
314.\".It Cm iso Pq Dv AF_ISO
315.\".Cm clnp , cltp , esis , tp
316.It Cm unix Pq Dv AF_UNIX
317.It Cm link Pq Dv AF_LINK
318.El
319.Pp
320The program will complain if
321.Ar protocol
322is unknown or if there is no statistics routine for it.
323.It Fl M
324Extract values associated with the name list from the specified core
325instead of the default
326.Pa /dev/kmem .
327.It Fl N
328Extract the name list from the specified system instead of the default,
329which is the kernel image the system has booted from.
330.It Fl n
331Show network addresses and ports as numbers.
332Normally
333.Nm
334attempts to resolve addresses and ports,
335and display them symbolically.
336.It Fl W
337In certain displays, avoid truncating addresses even if this causes
338some fields to overflow.
339.El
340.Pp
341The default display, for active sockets, shows the local
342and remote addresses, send and receive queue sizes (in bytes), protocol,
343and the internal state of the protocol.
344Address formats are of the form
345.Dq host.port
346or
347.Dq network.port
348if a socket's address specifies a network but no specific host address.
349When known, the host and network addresses are displayed symbolically
350according to the databases
351.Xr hosts 5
352and
353.Xr networks 5 ,
354respectively.
355If a symbolic name for an address is unknown, or if
356the
357.Fl n
358option is specified, the address is printed numerically, according
359to the address family.
360For more information regarding
361the Internet IPv4
362.Dq dot format ,
363refer to
364.Xr inet 3 .
365Unspecified,
366or
367.Dq wildcard ,
368addresses and ports appear as
369.Dq Li * .
370.Pp
371The interface display provides a table of cumulative
372statistics regarding packets transferred, errors, and collisions.
373The network addresses of the interface
374and the maximum transmission unit
375.Pq Dq mtu
376are also displayed.
377.Pp
378The routing table display indicates the available routes and their status.
379Each route consists of a destination host or network, and a gateway to use
380in forwarding packets.
381The flags field shows a collection of information about the route stored
382as binary choices.
383The individual flags are discussed in more detail in the
384.Xr route 8
385and
386.Xr route 4
387manual pages.
388The mapping between letters and flags is:
389.Bl -column ".Li W" ".Dv RTF_WASCLONED"
390.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
391.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
392.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
393.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
394.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
395.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
396.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
397.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
398.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
399.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
400.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
401.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
402.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
403.It Li S Ta Dv RTF_STATIC Ta "Manually added"
404.It Li U Ta Dv RTF_UP Ta "Route usable"
405.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
406.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
407.El
408.Pp
409Direct routes are created for each
410interface attached to the local host;
411the gateway field for such entries shows the address of the outgoing interface.
412The refcnt field gives the
413current number of active uses of the route.
414Connection oriented
415protocols normally hold on to a single route for the duration of
416a connection while connectionless protocols obtain a route while sending
417to the same destination.
418The use field provides a count of the number of packets
419sent using that route.
420The interface entry indicates the network interface utilized for the route.
421.Pp
422When
423.Nm
424is invoked with the
425.Fl w
426option and a
427.Ar wait
428interval argument, it displays a running count of statistics related to
429network interfaces.
430An obsolescent version of this option used a numeric parameter
431with no option, and is currently supported for backward compatibility.
432By default, this display summarizes information for all interfaces.
433Information for a specific interface may be displayed with the
434.Fl I
435option.
436.Pp
437The
438.Xr bpf 4
439flags displayed when
440.Nm
441is invoked with the
442.Fl B
443option represent the underlying parameters of the bpf peer.
444Each flag is
445represented as a single lower case letter.
446The mapping between the letters and flags in order of appearance are:
447.Bl -column ".Li i"
448.It Li p Ta Set if listening promiscuously
449.It Li i Ta Dv BIOCIMMEDIATE No has been set on the device
450.It Li f Ta Dv BIOCGHDRCMPLT No status: source link addresses are being
451filled automatically
452.It Li s Ta Dv BIOCGSEESENT No status: see packets originating locally and
453remotely on the interface.
454.It Li a Ta Packet reception generates a signal
455.It Li l Ta Dv BIOCLOCK No status: descriptor has been locked
456.El
457.Pp
458For more information about these flags, please refer to
459.Xr bpf 4 .
460.Pp
461The
462.Fl x
463flag causes netstat to output all the information recorded about data
464stored in the socket buffers.  The fields are:
465.Bl -column ".Li R-MBUF"
466.It Li R-MBUF Ta Number of mbufs in the receive queue.
467.It Li S-MBUF Ta Number of mbufs in the send queue.
468.It Li R-CLUS Ta Number of clusters, of any type, in the recieve
469queue.
470.It Li S-CLUS Ta Number of clusters, of any type, in the send queue.
471.It Li R-HIWA Ta Receive buffer high water mark, in bytes.
472.It Li S-HIWA Ta Send buffer high water mark, in bytes.
473.It Li R-LOWA Ta Receive buffer low water mark, in bytes.
474.It Li S-LOWA Ta Send buffer low water mark, in bytes.
475.It Li R-BCNT Ta Receive buffer byte count.
476.It Li S-BCNT Ta Send buffer byte count.
477.It Li R-BMAX Ta Maximum bytes that can be used in the receive buffer.
478.It Li S-BMAX Ta Maximum bytes that can be used in the send buffer.
479.El
480.Sh SEE ALSO
481.Xr fstat 1 ,
482.Xr nfsstat 1 ,
483.Xr ps 1 ,
484.Xr sockstat 1 ,
485.Xr bpf 4 ,
486.Xr inet 4 ,
487.Xr route 4 ,
488.Xr unix 4 ,
489.Xr hosts 5 ,
490.Xr networks 5 ,
491.Xr protocols 5 ,
492.Xr services 5 ,
493.Xr iostat 8 ,
494.Xr route 8 ,
495.Xr trpt 8 ,
496.Xr vmstat 8 ,
497.Xr mbuf 9
498.Sh HISTORY
499The
500.Nm
501command appeared in
502.Bx 4.2 .
503.Pp
504IPv6 support was added by WIDE/KAME project.
505.Sh BUGS
506The notion of errors is ill-defined.
507