xref: /freebsd/usr.bin/netstat/netstat.1 (revision 2357939bc239bd5334a169b62313806178dd8f30)
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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 AaLnSW
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.
122If
123.Fl W
124is also present, print interface names using a wider field size.
125.It Xo
126.Bk -words
127.Nm
128.Fl w Ar wait
129.Op Fl I Ar interface
130.Op Fl d
131.Op Fl M Ar core
132.Op Fl N Ar system
133.Ek
134.Xc
135At intervals of
136.Ar wait
137seconds,
138display the information regarding packet
139traffic on all configured network interfaces
140or a single
141.Ar interface .
142If
143.Fl d
144is also present, show the number of dropped packets.
145.It Xo
146.Bk -words
147.Nm
148.Fl s Op Fl s
149.Op Fl z
150.Op Fl f Ar protocol_family | Fl p Ar protocol
151.Op Fl M Ar core
152.Op Fl N Ar system
153.Ek
154.Xc
155Display system-wide statistics for each network protocol,
156for a particular
157.Ar protocol_family ,
158or for a single
159.Ar protocol .
160If
161.Fl s
162is repeated, counters with a value of zero are suppressed.
163If
164.Fl z
165is also present, reset statistic counters after displaying them.
166.It Xo
167.Bk -words
168.Nm
169.Fl i | I Ar interface Fl s
170.Op Fl f Ar protocol_family | Fl p Ar protocol
171.Op Fl M Ar core
172.Op Fl N Ar system
173.Ek
174.Xc
175Display per-interface statistics for each network protocol,
176for a particular
177.Ar protocol_family ,
178or for a single
179.Ar protocol .
180.It Xo
181.Bk -words
182.Nm
183.Fl m
184.Op Fl c
185.Op Fl M Ar core
186.Op Fl N Ar system
187.Ek
188.Xc
189Show statistics recorded by the memory management routines
190.Pq Xr mbuf 9 .
191The network manages a private pool of memory buffers.
192The
193.Fl c
194option shows per-cpu statistics for caching.
195.It Xo
196.Bk -words
197.Nm
198.Fl r
199.Op Fl AanW
200.Op Fl f Ar address_family
201.Op Fl M Ar core
202.Op Fl N Ar system
203.Ek
204.Xc
205Display the contents of all routing tables,
206or a routing table for a particular
207.Ar address_family .
208If
209.Fl A
210is also present,
211show the contents of the internal Patricia tree
212structures; used for debugging.
213If
214.Fl a
215is also present,
216show protocol-cloned routes
217(routes generated by an
218.Dv RTF_PRCLONING
219parent route);
220normally these routes are not shown.
221When
222.Fl W
223is also present,
224show the path MTU
225for each route,
226and print interface
227names with a wider
228field size.
229.It Xo
230.Bk -words
231.Nm
232.Fl rs
233.Op Fl s
234.Op Fl M Ar core
235.Op Fl N Ar system
236.Ek
237.Xc
238Display routing statistics.
239If
240.Fl s
241is repeated, counters with a value of zero are suppressed.
242.It Xo
243.Bk -words
244.Nm
245.Fl g
246.Op Fl W
247.Op Fl f Ar address_family
248.Op Fl M Ar core
249.Op Fl N Ar system
250.Ek
251.Xc
252Show information related to multicast (group address) routing.
253By default, show the IP Multicast virtual-interface and routing tables,
254and multicast group memberships.
255.It Xo
256.Bk -words
257.Nm
258.Fl gs
259.Op Fl s
260.Op Fl f Ar address_family
261.Op Fl M Ar core
262.Op Fl N Ar system
263.Ek
264.Xc
265Show multicast routing statistics.
266If
267.Fl s
268is repeated, counters with a value of zero are suppressed.
269.El
270.Pp
271Some options have the general meaning:
272.Bl -tag -width flag
273.It Fl f Ar address_family , Fl p Ar protocol
274Limit display to those records
275of the specified
276.Ar address_family
277or a single
278.Ar protocol .
279The following address families and protocols are recognized:
280.Pp
281.Bl -tag -width ".Cm netgraph , ng Pq Dv AF_NETGRAPH" -compact
282.It Em Family
283.Em Protocols
284.It Cm inet Pq Dv AF_INET
285.Cm bdg , divert , icmp , igmp , ip , ipsec , pim, tcp , udp
286.It Cm inet6 Pq Dv AF_INET6
287.Cm bdg , icmp6 , ip6 , ipsec6 , rip6 , tcp , udp
288.It Cm pfkey Pq Dv PF_KEY
289.Cm pfkey
290.It Cm atalk Pq Dv AF_APPLETALK
291.Cm ddp
292.It Cm netgraph , ng Pq Dv AF_NETGRAPH
293.Cm ctrl , data
294.It Cm ipx Pq Dv AF_IPX
295.Cm ipx , spx
296.\".It Cm ns Pq Dv AF_NS
297.\".Cm idp , ns_err , spp
298.\".It Cm iso Pq Dv AF_ISO
299.\".Cm clnp , cltp , esis , tp
300.It Cm unix Pq Dv AF_UNIX
301.It Cm link Pq Dv AF_LINK
302.El
303.Pp
304The program will complain if
305.Ar protocol
306is unknown or if there is no statistics routine for it.
307.It Fl M
308Extract values associated with the name list from the specified core
309instead of the default
310.Pa /dev/kmem .
311.It Fl N
312Extract the name list from the specified system instead of the default,
313which is the kernel image the system has booted from.
314.It Fl n
315Show network addresses and ports as numbers.
316Normally
317.Nm
318attempts to resolve addresses and ports,
319and display them symbolically.
320.It Fl W
321In certain displays, avoid truncating addresses even if this causes
322some fields to overflow.
323.El
324.Pp
325The default display, for active sockets, shows the local
326and remote addresses, send and receive queue sizes (in bytes), protocol,
327and the internal state of the protocol.
328Address formats are of the form
329.Dq host.port
330or
331.Dq network.port
332if a socket's address specifies a network but no specific host address.
333When known, the host and network addresses are displayed symbolically
334according to the databases
335.Xr hosts 5
336and
337.Xr networks 5 ,
338respectively.
339If a symbolic name for an address is unknown, or if
340the
341.Fl n
342option is specified, the address is printed numerically, according
343to the address family.
344For more information regarding
345the Internet IPv4
346.Dq dot format ,
347refer to
348.Xr inet 3 .
349Unspecified,
350or
351.Dq wildcard ,
352addresses and ports appear as
353.Dq Li * .
354.Pp
355The interface display provides a table of cumulative
356statistics regarding packets transferred, errors, and collisions.
357The network addresses of the interface
358and the maximum transmission unit
359.Pq Dq mtu
360are also displayed.
361.Pp
362The routing table display indicates the available routes and their status.
363Each route consists of a destination host or network, and a gateway to use
364in forwarding packets.
365The flags field shows a collection of information about the route stored
366as binary choices.
367The individual flags are discussed in more detail in the
368.Xr route 8
369and
370.Xr route 4
371manual pages.
372The mapping between letters and flags is:
373.Bl -column ".Li W" ".Dv RTF_WASCLONED"
374.It Li 1 Ta Dv RTF_PROTO1 Ta "Protocol specific routing flag #1"
375.It Li 2 Ta Dv RTF_PROTO2 Ta "Protocol specific routing flag #2"
376.It Li 3 Ta Dv RTF_PROTO3 Ta "Protocol specific routing flag #3"
377.It Li B Ta Dv RTF_BLACKHOLE Ta "Just discard pkts (during updates)"
378.It Li b Ta Dv RTF_BROADCAST Ta "The route represents a broadcast address"
379.It Li C Ta Dv RTF_CLONING Ta "Generate new routes on use"
380.It Li c Ta Dv RTF_PRCLONING Ta "Protocol-specified generate new routes on use"
381.It Li D Ta Dv RTF_DYNAMIC Ta "Created dynamically (by redirect)"
382.It Li G Ta Dv RTF_GATEWAY Ta "Destination requires forwarding by intermediary"
383.It Li H Ta Dv RTF_HOST Ta "Host entry (net otherwise)"
384.It Li L Ta Dv RTF_LLINFO Ta "Valid protocol to link address translation"
385.It Li M Ta Dv RTF_MODIFIED Ta "Modified dynamically (by redirect)"
386.It Li R Ta Dv RTF_REJECT Ta "Host or net unreachable"
387.It Li S Ta Dv RTF_STATIC Ta "Manually added"
388.It Li U Ta Dv RTF_UP Ta "Route usable"
389.It Li W Ta Dv RTF_WASCLONED Ta "Route was generated as a result of cloning"
390.It Li X Ta Dv RTF_XRESOLVE Ta "External daemon translates proto to link address"
391.El
392.Pp
393Direct routes are created for each
394interface attached to the local host;
395the gateway field for such entries shows the address of the outgoing interface.
396The refcnt field gives the
397current number of active uses of the route.
398Connection oriented
399protocols normally hold on to a single route for the duration of
400a connection while connectionless protocols obtain a route while sending
401to the same destination.
402The use field provides a count of the number of packets
403sent using that route.
404The interface entry indicates the network interface utilized for the route.
405.Pp
406When
407.Nm
408is invoked with the
409.Fl w
410option and a
411.Ar wait
412interval argument, it displays a running count of statistics related to
413network interfaces.
414An obsolescent version of this option used a numeric parameter
415with no option, and is currently supported for backward compatibility.
416By default, this display summarizes information for all interfaces.
417Information for a specific interface may be displayed with the
418.Fl I
419option.
420.Sh SEE ALSO
421.Xr fstat 1 ,
422.Xr nfsstat 1 ,
423.Xr ps 1 ,
424.Xr sockstat 1 ,
425.Xr inet 4 ,
426.Xr route 4 ,
427.Xr unix 4 ,
428.Xr hosts 5 ,
429.Xr networks 5 ,
430.Xr protocols 5 ,
431.Xr services 5 ,
432.Xr iostat 8 ,
433.Xr route 8 ,
434.Xr trpt 8 ,
435.Xr vmstat 8 ,
436.Xr mbuf 9
437.Sh HISTORY
438The
439.Nm
440command appeared in
441.Bx 4.2 .
442.Pp
443IPv6 support was added by WIDE/KAME project.
444.Sh BUGS
445The notion of errors is ill-defined.
446