xref: /freebsd/usr.bin/netstat/netstat.1 (revision dda5b39711dab90ae1c5624bdd6ff7453177df31)
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28.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
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31.Dd January 11, 2014
32.Dt NETSTAT 1
33.Os
34.Sh NAME
35.Nm netstat
36.Nd show network status
37.Sh DESCRIPTION
38The
39.Nm
40command symbolically displays the contents of various network-related
41data structures.
42There are a number of output formats,
43depending on the options for the information presented.
44.Bl -tag -width indent
45.It Xo
46.Bk -words
47.Nm
48.Op Fl 46AaLnSTWx
49.Op Fl f Ar protocol_family | Fl p Ar protocol
50.Op Fl M Ar core
51.Op Fl N Ar system
52.Ek
53.Xc
54Display a list of active sockets
55(protocol control blocks)
56for each network protocol,
57for a particular
58.Ar protocol_family ,
59or for a single
60.Ar protocol .
61If
62.Fl A
63is also present,
64show the address of a protocol control block (PCB)
65associated with a socket; used for debugging.
66If
67.Fl a
68is also present,
69show the state of all sockets;
70normally sockets used by server processes are not shown.
71If
72.Fl L
73is also present,
74show the size of the various listen queues.
75The first count shows the number of unaccepted connections,
76the second count shows the amount of unaccepted incomplete connections,
77and the third count is the maximum number of queued connections.
78If
79.Fl S
80is also present,
81show network addresses as numbers (as with
82.Fl n )
83but show ports symbolically.
84If
85.Fl x
86is present, display socket buffer and tcp timer statistics for each internet socket.
87When
88.Fl T
89is present, display information from the TCP control block, including
90retransmits, out-of-order packets received, and zero-sized windows advertised.
91.It Xo
92.Bk -words
93.Nm
94.Fl i | I Ar interface
95.Op Fl 46abdhnW
96.Op Fl f Ar address_family
97.Ek
98.Xc
99Show the state of all network interfaces or a single
100.Ar interface
101which have been auto-configured
102(interfaces statically configured into a system, but not
103located at boot time are not shown).
104An asterisk
105.Pq Dq Li *
106after an interface name indicates that the interface is
107.Dq down .
108If
109.Fl a
110is also present, multicast addresses currently in use are shown
111for each Ethernet interface and for each IP interface address.
112Multicast addresses are shown on separate lines following the interface
113address with which they are associated.
114If
115.Fl b
116is also present, show the number of bytes in and out.
117If
118.Fl d
119is also present, show the number of dropped packets.
120If
121.Fl h
122is also present, print all counters in human readable form.
123If
124.Fl W
125is also present, print interface names using a wider field size.
126.It Xo
127.Bk -words
128.Nm
129.Fl w Ar wait
130.Op Fl I Ar interface
131.Op Fl d
132.Op Fl M Ar core
133.Op Fl N Ar system
134.Op Fl q Ar howmany
135.Ek
136.Xc
137At intervals of
138.Ar wait
139seconds,
140display the information regarding packet
141traffic on all configured network interfaces
142or a single
143.Ar interface .
144If
145.Fl q
146is also present, exit after
147.Ar howmany
148outputs.
149If
150.Fl d
151is also present, show the number of dropped packets.
152.It Xo
153.Bk -words
154.Nm
155.Fl s Op Fl s
156.Op Fl 46z
157.Op Fl f Ar protocol_family | Fl p Ar protocol
158.Op Fl M Ar core
159.Op Fl N Ar system
160.Ek
161.Xc
162Display system-wide statistics for each network protocol,
163for a particular
164.Ar protocol_family ,
165or for a single
166.Ar protocol .
167If
168.Fl s
169is repeated, counters with a value of zero are suppressed.
170If
171.Fl z
172is also present, reset statistic counters after displaying them.
173.It Xo
174.Bk -words
175.Nm
176.Fl i | I Ar interface Fl s
177.Op Fl 46
178.Op Fl f Ar protocol_family | Fl p Ar protocol
179.Op Fl M Ar core
180.Op Fl N Ar system
181.Ek
182.Xc
183Display per-interface statistics for each network protocol,
184for a particular
185.Ar protocol_family ,
186or for a single
187.Ar protocol .
188.It Xo
189.Bk -words
190.Nm
191.Fl m
192.Op Fl M Ar core
193.Op Fl N Ar system
194.Ek
195.Xc
196Show statistics recorded by the memory management routines
197.Pq Xr mbuf 9 .
198The network manages a private pool of memory buffers.
199.It Xo
200.Bk -words
201.Nm
202.Fl B
203.Op Fl z
204.Op Fl I Ar interface
205.Ek
206.Xc
207Show statistics about
208.Xr bpf 4
209peers.
210This includes information like
211how many packets have been matched, dropped and received by the
212bpf device, also information about current buffer sizes and device
213states.
214.It Xo
215.Bk -words
216.Nm
217.Fl r
218.Op Fl 46AanW
219.Op Fl F Ar fibnum
220.Op Fl f Ar address_family
221.Op Fl M Ar core
222.Op Fl N Ar system
223.Ek
224.Xc
225Display the contents of routing tables.
226When
227.Fl f
228is specified, a routing table for a particular
229.Ar address_family
230is displayed.
231When
232.Fl F
233is specified, a routing table with the number
234.Ar fibnum
235is displayed.
236If the specified
237.Ar fibnum
238is -1 or
239.Fl F
240is not specified,
241the default routing table is displayed.
242If
243.Fl A
244is also present,
245show the contents of the internal Patricia tree
246structures; used for debugging.
247If
248.Fl a
249is also present,
250show protocol-cloned routes
251(routes generated by an
252.Dv RTF_PRCLONING
253parent route);
254normally these routes are not shown.
255When
256.Fl W
257is also present,
258show the path MTU
259for each route,
260and print interface
261names with a wider
262field size.
263.It Xo
264.Bk -words
265.Nm
266.Fl rs
267.Op Fl s
268.Op Fl M Ar core
269.Op Fl N Ar system
270.Ek
271.Xc
272Display routing statistics.
273If
274.Fl s
275is repeated, counters with a value of zero are suppressed.
276.It Xo
277.Bk -words
278.Nm
279.Fl g
280.Op Fl 46W
281.Op Fl f Ar address_family
282.Op Fl M Ar core
283.Op Fl N Ar system
284.Ek
285.Xc
286Display the contents of the multicast virtual interface tables,
287and multicast forwarding caches.
288Entries in these tables will appear only when the kernel is
289actively forwarding multicast sessions.
290This option is applicable only to the
291.Cm inet
292and
293.Cm inet6
294address families.
295.It Xo
296.Bk -words
297.Nm
298.Fl gs
299.Op Fl 46s
300.Op Fl f Ar address_family
301.Op Fl M Ar core
302.Op Fl N Ar system
303.Ek
304.Xc
305Show multicast routing statistics.
306If
307.Fl s
308is repeated, counters with a value of zero are suppressed.
309.It Xo
310.Bk -words
311.Nm
312.Fl Q
313.Ek
314.Xc
315Show
316.Xr netisr 9
317statistics.
318The flags field shows available ISR handlers:
319.Bl -column ".Li W" ".Dv NETISR_SNP_FLAGS_DRAINEDCPU"
320.It Li C Ta Dv NETISR_SNP_FLAGS_M2CPUID Ta "Able to map mbuf to cpu id"
321.It Li D Ta Dv NETISR_SNP_FLAGS_DRAINEDCPU  Ta "Has queue drain handler"
322.It Li F Ta Dv NETISR_SNP_FLAGS_M2FLOW Ta "Able to map mbuf to flow id"
323.El
324.El
325.Pp
326Some options have the general meaning:
327.Bl -tag -width flag
328.It Fl 4
329Is shorthand for
330.Fl f
331.Ar inet
332.It Fl 6
333Is shorthand for
334.Fl f
335.Ar inet6
336.It Fl f Ar address_family , Fl p Ar protocol
337Limit display to those records
338of the specified
339.Ar address_family
340or a single
341.Ar protocol .
342The following address families and protocols are recognized:
343.Pp
344.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
345.It Em Family
346.Em Protocols
347.It Cm inet Pq Dv AF_INET
348.Cm divert , icmp , igmp , ip , ipsec , pim, sctp , tcp , udp
349.It Cm inet6 Pq Dv AF_INET6
350.Cm icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
351.It Cm pfkey Pq Dv PF_KEY
352.Cm pfkey
353.It Cm atalk Pq Dv AF_APPLETALK
354.Cm ddp
355.It Cm netgraph , ng Pq Dv AF_NETGRAPH
356.Cm ctrl , data
357.It Cm unix Pq Dv AF_UNIX
358.It Cm link Pq Dv AF_LINK
359.El
360.Pp
361The program will complain if
362.Ar protocol
363is unknown or if there is no statistics routine for it.
364.It Fl M
365Extract values associated with the name list from the specified core
366instead of the default
367.Pa /dev/kmem .
368.It Fl N
369Extract the name list from the specified system instead of the default,
370which is the kernel image the system has booted from.
371.It Fl n
372Show network addresses and ports as numbers.
373Normally
374.Nm
375attempts to resolve addresses and ports,
376and display them symbolically.
377.It Fl W
378In certain displays, avoid truncating addresses even if this causes
379some fields to overflow.
380.El
381.Pp
382The default display, for active sockets, shows the local
383and remote addresses, send and receive queue sizes (in bytes), protocol,
384and the internal state of the protocol.
385Address formats are of the form
386.Dq host.port
387or
388.Dq network.port
389if a socket's address specifies a network but no specific host address.
390When known, the host and network addresses are displayed symbolically
391according to the databases
392.Xr hosts 5
393and
394.Xr networks 5 ,
395respectively.
396If a symbolic name for an address is unknown, or if
397the
398.Fl n
399option is specified, the address is printed numerically, according
400to the address family.
401For more information regarding
402the Internet IPv4
403.Dq dot format ,
404refer to
405.Xr inet 3 .
406Unspecified,
407or
408.Dq wildcard ,
409addresses and ports appear as
410.Dq Li * .
411.Pp
412The interface display provides a table of cumulative
413statistics regarding packets transferred, errors, and collisions.
414The network addresses of the interface
415and the maximum transmission unit
416.Pq Dq mtu
417are also displayed.
418.Pp
419The routing table display indicates the available routes and their status.
420Each route consists of a destination host or network, and a gateway to use
421in forwarding packets.
422The flags field shows a collection of information about the route stored
423as binary choices.
424The individual flags are discussed in more detail in the
425.Xr route 8
426and
427.Xr route 4
428manual pages.
429The mapping between letters and flags is:
430.Bl -column ".Li W" ".Dv RTF_WASCLONED"
431.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
432.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
433.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
434.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
435.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
436.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
437.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
438.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
439.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
440.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
441.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
442.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
443.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
444.It Li S Ta Dv RTF_STATIC Ta "Manually added"
445.It Li U Ta Dv RTF_UP Ta "Route usable"
446.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
447.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
448.El
449.Pp
450Direct routes are created for each
451interface attached to the local host;
452the gateway field for such entries shows the address of the outgoing interface.
453The refcnt field gives the
454current number of active uses of the route.
455Connection oriented
456protocols normally hold on to a single route for the duration of
457a connection while connectionless protocols obtain a route while sending
458to the same destination.
459The use field provides a count of the number of packets
460sent using that route.
461The interface entry indicates the network interface utilized for the route.
462.Pp
463When
464.Nm
465is invoked with the
466.Fl w
467option and a
468.Ar wait
469interval argument, it displays a running count of statistics related to
470network interfaces.
471An obsolescent version of this option used a numeric parameter
472with no option, and is currently supported for backward compatibility.
473By default, this display summarizes information for all interfaces.
474Information for a specific interface may be displayed with the
475.Fl I
476option.
477.Pp
478The
479.Xr bpf 4
480flags displayed when
481.Nm
482is invoked with the
483.Fl B
484option represent the underlying parameters of the bpf peer.
485Each flag is
486represented as a single lower case letter.
487The mapping between the letters and flags in order of appearance are:
488.Bl -column ".Li i"
489.It Li p Ta Set if listening promiscuously
490.It Li i Ta Dv BIOCIMMEDIATE No has been set on the device
491.It Li f Ta Dv BIOCGHDRCMPLT No status: source link addresses are being
492filled automatically
493.It Li s Ta Dv BIOCGSEESENT No status: see packets originating locally and
494remotely on the interface.
495.It Li a Ta Packet reception generates a signal
496.It Li l Ta Dv BIOCLOCK No status: descriptor has been locked
497.El
498.Pp
499For more information about these flags, please refer to
500.Xr bpf 4 .
501.Pp
502The
503.Fl x
504flag causes
505.Nm
506to output all the information recorded about data
507stored in the socket buffers.
508The fields are:
509.Bl -column ".Li R-MBUF"
510.It Li R-MBUF Ta Number of mbufs in the receive queue.
511.It Li S-MBUF Ta Number of mbufs in the send queue.
512.It Li R-CLUS Ta Number of clusters, of any type, in the receive
513queue.
514.It Li S-CLUS Ta Number of clusters, of any type, in the send queue.
515.It Li R-HIWA Ta Receive buffer high water mark, in bytes.
516.It Li S-HIWA Ta Send buffer high water mark, in bytes.
517.It Li R-LOWA Ta Receive buffer low water mark, in bytes.
518.It Li S-LOWA Ta Send buffer low water mark, in bytes.
519.It Li R-BCNT Ta Receive buffer byte count.
520.It Li S-BCNT Ta Send buffer byte count.
521.It Li R-BMAX Ta Maximum bytes that can be used in the receive buffer.
522.It Li S-BMAX Ta Maximum bytes that can be used in the send buffer.
523.El
524.Sh SEE ALSO
525.Xr fstat 1 ,
526.Xr nfsstat 1 ,
527.Xr procstat 1 ,
528.Xr ps 1 ,
529.Xr sockstat 1 ,
530.Xr bpf 4 ,
531.Xr inet 4 ,
532.Xr route 4 ,
533.Xr unix 4 ,
534.Xr hosts 5 ,
535.Xr networks 5 ,
536.Xr protocols 5 ,
537.Xr services 5 ,
538.Xr iostat 8 ,
539.Xr route 8 ,
540.Xr trpt 8 ,
541.Xr vmstat 8 ,
542.Xr mbuf 9
543.Sh HISTORY
544The
545.Nm
546command appeared in
547.Bx 4.2 .
548.Pp
549IPv6 support was added by WIDE/KAME project.
550.Sh BUGS
551The notion of errors is ill-defined.
552