Annotation of src/usr.bin/netstat/netstat.1, Revision 1.82
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1.82 ! guenther 33: .Dd $Mdocdate: August 12 2017 $
1.1 deraadt 34: .Dt NETSTAT 1
1.16 aaron 35: .Os
1.1 deraadt 36: .Sh NAME
37: .Nm netstat
38: .Nd show network status
39: .Sh SYNOPSIS
40: .Nm netstat
1.81 benno 41: .Op Fl AaBln
1.1 deraadt 42: .Op Fl f Ar address_family
1.59 blambert 43: .Op Fl p Ar protocol
1.1 deraadt 44: .Op Fl M Ar core
45: .Op Fl N Ar system
46: .Nm netstat
1.52 claudio 47: .Bk -words
1.48 pyr 48: .Op Fl bdFgilmnqrstu
1.1 deraadt 49: .Op Fl f Ar address_family
1.59 blambert 50: .Op Fl p Ar protocol
1.1 deraadt 51: .Op Fl M Ar core
52: .Op Fl N Ar system
1.52 claudio 53: .Op Fl T Ar tableid
54: .Ek
1.1 deraadt 55: .Nm netstat
1.68 tedu 56: .Op Fl bdhn
1.57 tedu 57: .Op Fl c Ar count
1.1 deraadt 58: .Op Fl I Ar interface
59: .Op Fl M Ar core
60: .Op Fl N Ar system
61: .Op Fl w Ar wait
62: .Nm netstat
1.61 bluhm 63: .Op Fl v
1.45 jaredy 64: .Op Fl M Ar core
65: .Op Fl N Ar system
66: .Fl P Ar pcbaddr
67: .Nm netstat
1.35 markus 68: .Op Fl s
1.1 deraadt 69: .Op Fl M Ar core
70: .Op Fl N Ar system
1.31 jmc 71: .Op Fl p Ar protocol
1.19 itojun 72: .Nm netstat
1.34 jmc 73: .Op Fl a
1.19 itojun 74: .Op Fl f Ar address_family
1.59 blambert 75: .Op Fl p Ar protocol
1.34 jmc 76: .Op Fl i | I Ar interface
1.42 reyk 77: .Nm netstat
78: .Op Fl W Ar interface
1.1 deraadt 79: .Sh DESCRIPTION
80: The
1.21 aaron 81: .Nm
1.1 deraadt 82: command symbolically displays the contents of various network-related
83: data structures.
84: There are a number of output formats,
85: depending on the options for the information presented.
1.21 aaron 86: .Pp
1.1 deraadt 87: The first form of the command displays a list of active sockets for
88: each protocol.
89: The second form presents the contents of one of the other network
90: data structures according to the option selected.
91: Using the third form, with a
92: .Ar wait
93: interval specified,
1.21 aaron 94: .Nm
1.1 deraadt 95: will continuously display the information regarding packet
96: traffic on the configured network interfaces.
1.61 bluhm 97: The fourth form displays internals of the protocol control block (PCB)
98: and the socket structure.
1.46 jmc 99: The fifth form displays statistics about the named protocol.
100: The sixth form displays per interface statistics for
1.30 jmc 101: the specified address family.
1.43 jmc 102: The final form displays per interface statistics for
103: the specified wireless (802.11) device.
1.1 deraadt 104: .Pp
1.12 aaron 105: The options are as follows:
1.22 aaron 106: .Bl -tag -width Ds
1.1 deraadt 107: .It Fl A
1.76 jmc 108: Show the address of any protocol control blocks associated with sockets;
109: useful for debugging e.g. with the
1.45 jaredy 110: .Fl P
111: flag.
1.75 claudio 112: When used with the
1.76 jmc 113: .Fl r
114: flag it shows the internal addresses of the routing table.
115: Only the super-user can see these addresses;
116: unprivileged users will see them as 0x0.
1.1 deraadt 117: .It Fl a
118: With the default display,
119: show the state of all sockets; normally sockets used by
120: server processes are not shown.
1.63 jsing 121: .It Fl B
122: With the default display,
123: show buffer sizes for TCP sockets.
124: This includes the send window size, receive window size and congestion
125: window size.
1.24 camield 126: .It Fl b
1.34 jmc 127: With the interface display (options
128: .Fl I
129: or
1.24 camield 130: .Fl i ) ,
131: show bytes in and out, instead of packet statistics.
1.57 tedu 132: .It Fl c Ar count
133: Display
134: .Ar count
135: updates, then exit.
136: This option has no effect unless
137: .Fl w
138: is specified as well.
1.1 deraadt 139: .It Fl d
1.34 jmc 140: With either the interface display (options
141: .Fl I
142: or
143: .Fl i )
144: or an interval (option
145: .Fl w ) ,
1.1 deraadt 146: show the number of dropped packets.
1.48 pyr 147: .It Fl F
148: When showing routes, only show routes whose gateway are in the
149: same address family as the destination.
1.16 aaron 150: .It Fl f Ar address_family
1.1 deraadt 151: Limit statistics or address control block reports to those
152: of the specified
1.12 aaron 153: .Ar address_family .
1.21 aaron 154: .Pp
155: The following address families are recognized:
1.65 jmc 156: .Bl -column "Address Family" "AF_APPLETA" "Description" -offset indent
1.21 aaron 157: .It Sy "Address Family" Ta Sy "Constant" Ta Sy "Description"
1.32 jmc 158: .It "inet" Ta Dv "AF_INET" Ta "IP Version 4"
159: .It "inet6" Ta Dv "AF_INET6" Ta "IP Version 6"
1.82 ! guenther 160: .It "local" Ta Dv "AF_UNIX" Ta "Alias for unix"
1.55 mk 161: .It "mpls" Ta Dv "AF_MPLS" Ta "MPLS"
1.32 jmc 162: .It "unix" Ta Dv "AF_UNIX" Ta "Local to Host (i.e., pipes)"
1.21 aaron 163: .El
1.68 tedu 164: .It Fl h
165: Use unit suffixes to reduce the number of digits shown with the
166: .Fl b
167: and
168: .Fl w
169: options.
1.1 deraadt 170: .It Fl g
171: Show information related to multicast (group address) routing.
1.34 jmc 172: By default, show the IP multicast virtual-interface and routing tables.
1.1 deraadt 173: If the
174: .Fl s
175: option is also present, show multicast routing statistics.
1.16 aaron 176: .It Fl I Ar interface
1.21 aaron 177: Show information about the specified
178: .Ar interface ;
1.1 deraadt 179: used with a
180: .Ar wait
181: interval as described below.
1.21 aaron 182: .Pp
1.19 itojun 183: If the
184: .Fl f Ar address_family
185: option (with the
186: .Fl s
1.30 jmc 187: option) is present, show per-interface
188: statistics on the given interface for the specified
189: .Ar address_family .
1.1 deraadt 190: .It Fl i
191: Show the state of interfaces which have been auto-configured
1.21 aaron 192: (interfaces statically configured into a system but not
193: located at boot-time are not shown).
194: .Pp
1.19 itojun 195: If the
196: .Fl f Ar address_family
197: option (with the
198: .Fl s
1.30 jmc 199: option) is present, show per-interface statistics on all interfaces
1.21 aaron 200: for the specified
1.30 jmc 201: .Ar address_family .
1.31 jmc 202: .It Fl l
1.81 benno 203: With the default display,
204: show only listening sockets.
1.31 jmc 205: With the
206: .Fl g
207: option, display wider fields for the IPv6 multicast routing table
208: .Qq Origin
209: and
210: .Qq Group
211: columns.
1.17 deraadt 212: .It Fl M Ar core
1.1 deraadt 213: Extract values associated with the name list from the specified core
1.27 miod 214: instead of the running kernel.
1.1 deraadt 215: .It Fl m
216: Show statistics recorded by the memory management routines
217: (the network manages a private pool of memory buffers).
1.17 deraadt 218: .It Fl N Ar system
1.27 miod 219: Extract the name list from the specified system instead of the running kernel.
1.1 deraadt 220: .It Fl n
221: Show network addresses as numbers (normally
1.21 aaron 222: .Nm
1.1 deraadt 223: interprets addresses and attempts to display them
224: symbolically).
225: This option may be used with any of the display formats.
1.45 jaredy 226: .It Fl P Ar pcbaddr
1.75 claudio 227: Display the contents of the protocol control block (PCB)
1.61 bluhm 228: located at the kernel virtual address
1.45 jaredy 229: .Ar pcbaddr .
230: PCB addresses can be obtained using the
231: .Fl A
232: flag.
1.61 bluhm 233: When used with the
234: .Fl v
235: option, also print socket, domain and protocol specific structures.
1.76 jmc 236: Only the super-user can use the
237: .Fl P
238: option.
1.80 jca 239: .Pp
240: The
241: .Fl P
242: option requires the ability to open
243: .Pa /dev/kmem
244: which may be restricted based upon the value of the
245: .Ar kern.allowkmem
246: .Xr sysctl 8 .
1.16 aaron 247: .It Fl p Ar protocol
1.35 markus 248: Restrict the output to
1.12 aaron 249: .Ar protocol ,
1.21 aaron 250: which is either a well-known name for a protocol or an alias for it.
251: Some protocol names and aliases are listed in the file
1.1 deraadt 252: .Pa /etc/protocols .
253: The program will complain if
254: .Ar protocol
1.35 markus 255: is unknown.
256: If the
257: .Fl s
258: option is specified, the per-protocol statistics are displayed.
259: Otherwise the states of the matching sockets are shown.
1.26 brian 260: .It Fl q
261: Only show interfaces that have seen packets (or bytes if
262: .Fl b
1.34 jmc 263: is specified).
1.1 deraadt 264: .It Fl r
265: Show the routing tables.
1.21 aaron 266: If the
1.1 deraadt 267: .Fl s
1.21 aaron 268: option is also specified, show routing statistics instead.
1.60 sobrado 269: When used with the
270: .Fl v
271: option, also print routing labels.
1.26 brian 272: .It Fl s
273: Show per-protocol statistics.
274: If this option is repeated, counters with a value of zero are suppressed.
1.51 claudio 275: .It Fl T Ar tableid
1.67 mikeb 276: Select an alternate routing table to query.
277: The default is to use the current routing table.
1.31 jmc 278: .It Fl t
279: With the
280: .Fl i
281: option, display the current value of the watchdog timer function.
282: .It Fl u
283: Limit statistics or address control block reports to the
284: .Dv AF_UNIX
285: address family.
1.10 peter 286: .It Fl v
1.60 sobrado 287: Show extra (verbose) detail for the routing tables
288: .Pq Fl r ,
289: or avoid truncation of long addresses.
1.61 bluhm 290: When used with the
291: .Fl P
292: option, also print socket, domain and protocol specific structures.
1.42 reyk 293: .It Fl W Ar interface
294: (IEEE 802.11 devices only)
295: Show per-interface IEEE 802.11 wireless statistics.
1.1 deraadt 296: .It Fl w Ar wait
297: Show network interface statistics at intervals of
298: .Ar wait
299: seconds.
300: .El
301: .Pp
302: The default display, for active sockets, shows the local
303: and remote addresses, send and receive queue sizes (in bytes), protocol,
304: and the internal state of the protocol.
1.21 aaron 305: .Pp
306: Address formats are of the form
307: .Dq host.port
308: or
309: .Dq network.port
1.1 deraadt 310: if a socket's address specifies a network but no specific host address.
1.72 schwarze 311: When known, the host addresses are displayed symbolically
312: according to the
313: .Xr hosts 5
314: database.
1.21 aaron 315: If a symbolic name for an address is unknown, or if the
1.1 deraadt 316: .Fl n
317: option is specified, the address is printed numerically, according
318: to the address family.
1.21 aaron 319: .Pp
320: For more information regarding the Internet
321: .Dq dot format ,
1.1 deraadt 322: refer to
1.71 jmc 323: .Xr inet_ntop 3 .
1.34 jmc 324: Unspecified or
1.21 aaron 325: .Dq wildcard
326: addresses and ports appear as a single
1.34 jmc 327: .Sq * .
1.6 deraadt 328: If a local port number is registered as being in use for RPC by
1.12 aaron 329: .Xr portmap 8 ,
1.11 aaron 330: its RPC service name or RPC service number will be printed in
1.21 aaron 331: .Dq []
332: immediately after the port number.
1.1 deraadt 333: .Pp
334: The interface display provides a table of cumulative
335: statistics regarding packets transferred, errors, and collisions.
336: The network addresses of the interface
1.21 aaron 337: and the maximum transmission unit (MTU) are also displayed.
1.1 deraadt 338: .Pp
1.21 aaron 339: The routing table display indicates the available routes and their status.
340: Each route consists of a destination host or network and
341: a gateway to use in forwarding packets.
342: If the destination is a
343: network in numeric format, the netmask (in /24 style format) is appended.
344: The flags field shows a collection of information about
345: the route stored as binary choices.
346: The individual flags are discussed in more detail in the
1.1 deraadt 347: .Xr route 8
348: and
349: .Xr route 4
350: manual pages.
1.21 aaron 351: .Pp
1.1 deraadt 352: The mapping between letters and flags is:
1.66 jmc 353: .Bl -column "1" "RTF_BLACKHOLE" "Protocol specific routing flag #1."
354: .It 1 Ta RTF_PROTO1 Ta "Protocol specific routing flag #1."
355: .It 2 Ta RTF_PROTO2 Ta "Protocol specific routing flag #2."
356: .It 3 Ta RTF_PROTO3 Ta "Protocol specific routing flag #3."
357: .It B Ta RTF_BLACKHOLE Ta "Just discard pkts (during updates)."
1.70 mpi 358: .It b Ta RTF_BROADCAST Ta "Correspond to a local broadcast address."
1.66 jmc 359: .It C Ta RTF_CLONING Ta "Generate new routes on use."
360: .It c Ta RTF_CLONED Ta "Cloned routes (generated from RTF_CLONING)."
361: .It D Ta RTF_DYNAMIC Ta "Created dynamically (by redirect)."
1.79 bluhm 362: .It d Ta RTF_DONE Ta "Completed (for routing messages only)."
1.66 jmc 363: .It G Ta RTF_GATEWAY Ta "Destination requires forwarding by intermediary."
364: .It H Ta RTF_HOST Ta "Host entry (net otherwise)."
1.79 bluhm 365: .It h Ta RTF_CACHED Ta "Referenced by gateway route."
1.66 jmc 366: .It L Ta RTF_LLINFO Ta "Valid protocol to link address translation."
1.70 mpi 367: .It l Ta RTF_LOCAL Ta "Correspond to a local address."
1.66 jmc 368: .It M Ta RTF_MODIFIED Ta "Modified dynamically (by redirect)."
1.78 mpi 369: .It m Ta RTF_MULTICAST Ta "Correspond to a multicast address."
1.79 bluhm 370: .It n Ta RTF_CONNECTED Ta "Interface route."
1.66 jmc 371: .It P Ta RTF_MPATH Ta "Multipath route."
372: .It R Ta RTF_REJECT Ta "Host or net unreachable."
373: .It S Ta RTF_STATIC Ta "Manually added."
374: .It T Ta RTF_MPLS Ta "MPLS route."
375: .It U Ta RTF_UP Ta "Route usable."
1.1 deraadt 376: .El
377: .Pp
1.21 aaron 378: Direct routes are created for each interface attached to the local host;
1.1 deraadt 379: the gateway field for such entries shows the address of the outgoing interface.
1.21 aaron 380: The refcnt field gives the current number of active uses of the route.
381: Connection oriented protocols normally hold on to a single route for the
382: duration of a connection while connectionless protocols obtain a route while
383: sending to the same destination.
384: The use field provides a count of the number of packets sent using that route.
385: The MTU entry shows the MTU associated with that route.
386: This MTU value is used as the basis for the TCP maximum segment size (MSS).
1.34 jmc 387: The
388: .Sq L
389: flag appended to the MTU value indicates that the value is
390: locked, and that path MTU discovery is turned off for that route.
1.21 aaron 391: A
1.1 deraadt 392: .Sq -
1.12 aaron 393: indicates that the MTU for this route has not been set, and a default
1.21 aaron 394: TCP maximum segment size will be used.
395: The interface entry indicates the network interface utilized for the route.
1.1 deraadt 396: .Pp
397: When
1.21 aaron 398: .Nm
1.1 deraadt 399: is invoked with the
400: .Fl w
401: option and a
402: .Ar wait
403: interval argument, it displays a running count of statistics related to
404: network interfaces.
405: An obsolescent version of this option used a numeric parameter
406: with no option, and is currently supported for backward compatibility.
407: This display consists of a column for the primary interface (the first
408: interface found during autoconfiguration) and a column summarizing
409: information for all interfaces.
410: The primary interface may be replaced with another interface with the
411: .Fl I
412: option.
413: The first line of each screen of information contains a summary since the
1.21 aaron 414: system was last rebooted.
415: Subsequent lines of output show values accumulated over the preceding interval.
1.1 deraadt 416: .Sh SEE ALSO
1.47 jmc 417: .Xr fstat 1 ,
1.1 deraadt 418: .Xr nfsstat 1 ,
419: .Xr ps 1 ,
1.47 jmc 420: .Xr systat 1 ,
1.53 jmc 421: .Xr tcpbench 1 ,
1.47 jmc 422: .Xr top 1 ,
1.71 jmc 423: .Xr inet_ntop 3 ,
1.21 aaron 424: .Xr netintro 4 ,
1.34 jmc 425: .Xr route 4 ,
1.1 deraadt 426: .Xr hosts 5 ,
427: .Xr protocols 5 ,
428: .Xr services 5 ,
1.15 alex 429: .Xr iostat 8 ,
1.34 jmc 430: .Xr portmap 8 ,
1.47 jmc 431: .Xr pstat 8 ,
1.34 jmc 432: .Xr route 8 ,
1.40 jmc 433: .Xr tcpdrop 8 ,
1.1 deraadt 434: .Xr trpt 8 ,
435: .Xr vmstat 8
436: .Sh HISTORY
437: The
1.21 aaron 438: .Nm
1.1 deraadt 439: command appeared in
440: .Bx 4.2 .
1.62 schwarze 441: IPv6 support was added by the WIDE/KAME project.
1.1 deraadt 442: .Sh BUGS
443: The notion of errors is ill-defined.