xref: /freebsd/usr.bin/netstat/netstat.1 (revision 729362425c09cf6b362366aabc6fb547eee8035a)
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32.\"	@(#)netstat.1	8.8 (Berkeley) 4/18/94
33.\" $FreeBSD$
34.\"
35.Dd September 7, 2001
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 AaLlnSW
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 abdnt
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 t
121is also present, show the contents of watchdog timers.
122.It Xo
123.Bk -words
124.Nm
125.Fl w Ar wait
126.Op Fl I Ar interface
127.Op Fl d
128.Op Fl M Ar core
129.Op Fl N Ar system
130.Ek
131.Xc
132At intervals of
133.Ar wait
134seconds,
135display the information regarding packet
136traffic on all configured network interfaces
137or a single
138.Ar interface .
139If
140.Fl d
141is also present, show the number of dropped packets.
142.It Xo
143.Bk -words
144.Nm
145.Fl s Op Fl s
146.Op Fl z
147.Op Fl f Ar protocol_family | Fl p Ar protocol
148.Op Fl M Ar core
149.Op Fl N Ar system
150.Ek
151.Xc
152Display system-wide statistics for each network protocol,
153for a particular
154.Ar protocol_family ,
155or for a single
156.Ar protocol .
157If
158.Fl s
159is repeated, counters with a value of zero are suppressed.
160If
161.Fl z
162is also present, reset statistic counters after displaying them.
163.It Xo
164.Bk -words
165.Nm
166.Fl i | I Ar interface Fl s
167.Op Fl f Ar protocol_family | Fl p Ar protocol
168.Op Fl M Ar core
169.Op Fl N Ar system
170.Ek
171.Xc
172Display per-interface statistics for each network protocol,
173for a particular
174.Ar protocol_family ,
175or for a single
176.Ar protocol .
177.It Xo
178.Bk -words
179.Nm
180.Fl m
181.Op Fl M Ar core
182.Op Fl N Ar system
183.Ek
184.Xc
185Show statistics recorded by the memory management routines
186.Pq Xr mbuf 9 .
187The network manages a private pool of memory buffers.
188.It Xo
189.Bk -words
190.Nm
191.Fl r
192.Op Fl AalnW
193.Op Fl f Ar address_family
194.Op Fl M Ar core
195.Op Fl N Ar system
196.Ek
197.Xc
198Display the contents of all routing tables,
199or a routing table for a particular
200.Ar address_family .
201If
202.Fl A
203is also present,
204show the contents of the internal Patricia tree
205structures; used for debugging.
206If
207.Fl a
208is also present,
209show protocol-cloned routes
210(routes generated by an
211.Dv RTF_PRCLONING
212parent route);
213normally these routes are not shown.
214When
215.Fl W
216or
217.Fl l
218is also present,
219show the path MTU
220for each route.
221.It Xo
222.Bk -words
223.Nm
224.Fl rs
225.Op Fl s
226.Op Fl M Ar core
227.Op Fl N Ar system
228.Ek
229.Xc
230Display routing statistics.
231If
232.Fl s
233is repeated, counters with a value of zero are suppressed.
234.It Xo
235.Bk -words
236.Nm
237.Fl g
238.Op Fl lW
239.Op Fl f Ar address_family
240.Op Fl M Ar core
241.Op Fl N Ar system
242.Ek
243.Xc
244Show information related to multicast (group address) routing.
245By default, show the IP Multicast virtual-interface and routing tables.
246.It Xo
247.Bk -words
248.Nm
249.Fl gs
250.Op Fl s
251.Op Fl f Ar address_family
252.Op Fl M Ar core
253.Op Fl N Ar system
254.Ek
255.Xc
256Show multicast routing statistics.
257If
258.Fl s
259is repeated, counters with a value of zero are suppressed.
260.El
261.Pp
262Some options have the general meaning:
263.Bl -tag -width flag
264.It Fl f Ar address_family , Fl p Ar protocol
265Limit display to those records
266of the specified
267.Ar address_family
268or a single
269.Ar protocol .
270The following address families and protocols are recognized:
271.Pp
272.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
273.It Em Family
274.Em Protocols
275.It Cm inet Pq Dv AF_INET
276.Cm bdg , divert , icmp , igmp , ip , ipsec , tcp , udp
277.It Cm inet6 Pq Dv AF_INET6
278.Cm bdg , icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
279.It Cm pfkey Pq Dv PF_KEY
280.Cm pfkey
281.It Cm atalk Pq Dv AF_APPLETALK
282.Cm ddp
283.It Cm netgraph , ng Pq Dv AF_NETGRAPH
284.Cm ctrl , data
285.It Cm ipx Pq Dv AF_IPX
286.Cm ipx , spx
287.\".It Cm ns Pq Dv AF_NS
288.\".Cm idp , ns_err , spp
289.\".It Cm iso Pq Dv AF_ISO
290.\".Cm clnp , cltp , esis , tp
291.It Cm unix Pq Dv AF_UNIX
292.It Cm link Pq Dv AF_LINK
293.El
294.Pp
295The program will complain if
296.Ar protocol
297is unknown or if there is no statistics routine for it.
298.It Fl l
299The
300.Fl l
301option is equivalent to
302.Fl W .
303.It Fl M
304Extract values associated with the name list from the specified core
305instead of the default
306.Pa /dev/kmem .
307.It Fl N
308Extract the name list from the specified system instead of the default,
309which is the kernel image the system has booted from.
310.It Fl n
311Show network addresses and ports as numbers.
312Normally
313.Nm
314attempts to resolve addresses and ports,
315and display them symbolically.
316.It Fl W
317In certain displays, avoid truncating addresses even if this causes
318some fields to overflow.
319.El
320.Pp
321The default display, for active sockets, shows the local
322and remote addresses, send and receive queue sizes (in bytes), protocol,
323and the internal state of the protocol.
324Address formats are of the form
325.Dq host.port
326or
327.Dq network.port
328if a socket's address specifies a network but no specific host address.
329When known, the host and network addresses are displayed symbolically
330according to the databases
331.Xr hosts 5
332and
333.Xr networks 5 ,
334respectively.
335If a symbolic name for an address is unknown, or if
336the
337.Fl n
338option is specified, the address is printed numerically, according
339to the address family.
340For more information regarding
341the Internet IPv4
342.Dq dot format ,
343refer to
344.Xr inet 3 .
345Unspecified,
346or
347.Dq wildcard ,
348addresses and ports appear as
349.Dq Li * .
350.Pp
351The interface display provides a table of cumulative
352statistics regarding packets transferred, errors, and collisions.
353The network addresses of the interface
354and the maximum transmission unit
355.Pq Dq mtu
356are also displayed.
357.Pp
358The routing table display indicates the available routes and their status.
359Each route consists of a destination host or network, and a gateway to use
360in forwarding packets.
361The flags field shows a collection of information about the route stored
362as binary choices.
363The individual flags are discussed in more detail in the
364.Xr route 8
365and
366.Xr route 4
367manual pages.
368The mapping between letters and flags is:
369.Bl -column ".Li W" ".Dv RTF_WASCLONED"
370.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
371.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
372.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
373.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
374.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
375.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
376.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
377.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
378.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
379.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
380.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
381.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
382.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
383.It Li S Ta Dv RTF_STATIC Ta "Manually added"
384.It Li U Ta Dv RTF_UP Ta "Route usable"
385.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
386.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
387.El
388.Pp
389Direct routes are created for each
390interface attached to the local host;
391the gateway field for such entries shows the address of the outgoing interface.
392The refcnt field gives the
393current number of active uses of the route.
394Connection oriented
395protocols normally hold on to a single route for the duration of
396a connection while connectionless protocols obtain a route while sending
397to the same destination.
398The use field provides a count of the number of packets
399sent using that route.
400The interface entry indicates the network interface utilized for the route.
401.Pp
402When
403.Nm
404is invoked with the
405.Fl w
406option and a
407.Ar wait
408interval argument, it displays a running count of statistics related to
409network interfaces.
410An obsolescent version of this option used a numeric parameter
411with no option, and is currently supported for backward compatibility.
412By default, this display summarizes information for all interfaces.
413Information for a specific interface may be displayed with the
414.Fl I
415option.
416.Sh SEE ALSO
417.Xr fstat 1 ,
418.Xr nfsstat 1 ,
419.Xr ps 1 ,
420.Xr sockstat 1 ,
421.Xr inet 4 ,
422.Xr route 4 ,
423.Xr unix 4 ,
424.Xr hosts 5 ,
425.Xr networks 5 ,
426.Xr protocols 5 ,
427.Xr services 5 ,
428.Xr iostat 8 ,
429.Xr route 8 ,
430.Xr trpt 8 ,
431.Xr vmstat 8 ,
432.Xr mbuf 9
433.Sh HISTORY
434The
435.Nm
436command appeared in
437.Bx 4.2 .
438.Pp
439IPv6 support was added by WIDE/KAME project.
440.Sh BUGS
441The notion of errors is ill-defined.
442