.\" $OpenBSD: netstat.1,v 1.72 2014/10/23 16:45:57 schwarze Exp $ .\" $NetBSD: netstat.1,v 1.11 1995/10/03 21:42:43 thorpej Exp $ .\" .\" Copyright (c) 1983, 1990, 1992, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" from: @(#)netstat.1 8.8 (Berkeley) 4/18/94 .\" .Dd $Mdocdate: October 23 2014 $ .Dt NETSTAT 1 .Os .Sh NAME .Nm netstat .Nd show network status .Sh SYNOPSIS .Nm netstat .Op Fl AaBn .Op Fl f Ar address_family .Op Fl p Ar protocol .Op Fl M Ar core .Op Fl N Ar system .Nm netstat .Bk -words .Op Fl bdFgilmnqrstu .Op Fl f Ar address_family .Op Fl p Ar protocol .Op Fl M Ar core .Op Fl N Ar system .Op Fl T Ar tableid .Ek .Nm netstat .Op Fl bdhn .Op Fl c Ar count .Op Fl I Ar interface .Op Fl M Ar core .Op Fl N Ar system .Op Fl w Ar wait .Nm netstat .Op Fl v .Op Fl M Ar core .Op Fl N Ar system .Fl P Ar pcbaddr .Nm netstat .Op Fl s .Op Fl M Ar core .Op Fl N Ar system .Op Fl p Ar protocol .Nm netstat .Op Fl a .Op Fl f Ar address_family .Op Fl p Ar protocol .Op Fl i | I Ar interface .Nm netstat .Op Fl W Ar interface .Sh DESCRIPTION The .Nm command symbolically displays the contents of various network-related data structures. There are a number of output formats, depending on the options for the information presented. .Pp The first form of the command displays a list of active sockets for each protocol. The second form presents the contents of one of the other network data structures according to the option selected. Using the third form, with a .Ar wait interval specified, .Nm will continuously display the information regarding packet traffic on the configured network interfaces. The fourth form displays internals of the protocol control block (PCB) and the socket structure. The fifth form displays statistics about the named protocol. The sixth form displays per interface statistics for the specified address family. The final form displays per interface statistics for the specified wireless (802.11) device. .Pp The options are as follows: .Bl -tag -width Ds .It Fl A With the default display, show the address of any protocol control blocks associated with sockets; used for debugging, e.g. with the .Fl P flag. .It Fl a With the default display, show the state of all sockets; normally sockets used by server processes are not shown. With the interface display (options .Fl I or .Fl i ) , show multicast addresses. .It Fl B With the default display, show buffer sizes for TCP sockets. This includes the send window size, receive window size and congestion window size. .It Fl b With the interface display (options .Fl I or .Fl i ) , show bytes in and out, instead of packet statistics. .It Fl c Ar count Display .Ar count updates, then exit. This option has no effect unless .Fl w is specified as well. .It Fl d With either the interface display (options .Fl I or .Fl i ) or an interval (option .Fl w ) , show the number of dropped packets. .It Fl F When showing routes, only show routes whose gateway are in the same address family as the destination. .It Fl f Ar address_family Limit statistics or address control block reports to those of the specified .Ar address_family . .Pp The following address families are recognized: .Bl -column "Address Family" "AF_APPLETA" "Description" -offset indent .It Sy "Address Family" Ta Sy "Constant" Ta Sy "Description" .It "encap" Ta Dv "PF_KEY" Ta "IPsec" .It "inet" Ta Dv "AF_INET" Ta "IP Version 4" .It "inet6" Ta Dv "AF_INET6" Ta "IP Version 6" .It "local" Ta Dv "AF_LOCAL" Ta "Local to Host (i.e., pipes)" .It "mpls" Ta Dv "AF_MPLS" Ta "MPLS" .It "pflow" Ta Dv "PF_FLOW" Ta "pflow data export" .It "unix" Ta Dv "AF_UNIX" Ta "Local to Host (i.e., pipes)" .El .It Fl h Use unit suffixes to reduce the number of digits shown with the .Fl b and .Fl w options. .It Fl g Show information related to multicast (group address) routing. By default, show the IP multicast virtual-interface and routing tables. If the .Fl s option is also present, show multicast routing statistics. .It Fl I Ar interface Show information about the specified .Ar interface ; used with a .Ar wait interval as described below. .Pp If the .Fl a option is also present, multicast addresses currently in use are shown for the given interface and for each IP interface address. Multicast addresses are shown on separate lines following the interface address with which they are associated. .Pp If the .Fl f Ar address_family option (with the .Fl s option) is present, show per-interface statistics on the given interface for the specified .Ar address_family . .It Fl i Show the state of interfaces which have been auto-configured (interfaces statically configured into a system but not located at boot-time are not shown). .Pp If the .Fl a option is also present, multicast addresses currently in use are shown for each Ethernet interface and for each IP interface address. Multicast addresses are shown on separate lines following the interface address with which they are associated. .Pp If the .Fl f Ar address_family option (with the .Fl s option) is present, show per-interface statistics on all interfaces for the specified .Ar address_family . .It Fl l With the .Fl g option, display wider fields for the IPv6 multicast routing table .Qq Origin and .Qq Group columns. .It Fl M Ar core Extract values associated with the name list from the specified core instead of the running kernel. .It Fl m Show statistics recorded by the memory management routines (the network manages a private pool of memory buffers). .It Fl N Ar system Extract the name list from the specified system instead of the running kernel. .It Fl n Show network addresses as numbers (normally .Nm interprets addresses and attempts to display them symbolically). This option may be used with any of the display formats. .It Fl P Ar pcbaddr Display the contents of the socket or protocol control block (PCB) located at the kernel virtual address .Ar pcbaddr . PCB addresses can be obtained using the .Fl A flag. When used with the .Fl v option, also print socket, domain and protocol specific structures. .It Fl p Ar protocol Restrict the output to .Ar protocol , which is either a well-known name for a protocol or an alias for it. Some protocol names and aliases are listed in the file .Pa /etc/protocols . The program will complain if .Ar protocol is unknown. If the .Fl s option is specified, the per-protocol statistics are displayed. Otherwise the states of the matching sockets are shown. .It Fl q Only show interfaces that have seen packets (or bytes if .Fl b is specified). .It Fl r Show the routing tables. If the .Fl s option is also specified, show routing statistics instead. When used with the .Fl v option, also print routing labels. .It Fl s Show per-protocol statistics. If this option is repeated, counters with a value of zero are suppressed. .It Fl T Ar tableid Select an alternate routing table to query. The default is to use the current routing table. .It Fl t With the .Fl i option, display the current value of the watchdog timer function. .It Fl u Limit statistics or address control block reports to the .Dv AF_UNIX address family. .It Fl v Show extra (verbose) detail for the routing tables .Pq Fl r , or avoid truncation of long addresses. When used with the .Fl P option, also print socket, domain and protocol specific structures. .It Fl W Ar interface (IEEE 802.11 devices only) Show per-interface IEEE 802.11 wireless statistics. .It Fl w Ar wait Show network interface statistics at intervals of .Ar wait seconds. .El .Pp The default display, for active sockets, shows the local and remote addresses, send and receive queue sizes (in bytes), protocol, and the internal state of the protocol. .Pp Address formats are of the form .Dq host.port or .Dq network.port if a socket's address specifies a network but no specific host address. When known, the host addresses are displayed symbolically according to the .Xr hosts 5 database. If a symbolic name for an address is unknown, or if the .Fl n option is specified, the address is printed numerically, according to the address family. .Pp For more information regarding the Internet .Dq dot format , refer to .Xr inet_ntop 3 . Unspecified or .Dq wildcard addresses and ports appear as a single .Sq * . If a local port number is registered as being in use for RPC by .Xr portmap 8 , its RPC service name or RPC service number will be printed in .Dq [] immediately after the port number. .Pp The interface display provides a table of cumulative statistics regarding packets transferred, errors, and collisions. The network addresses of the interface and the maximum transmission unit (MTU) are also displayed. .Pp The routing table display indicates the available routes and their status. Each route consists of a destination host or network and a gateway to use in forwarding packets. If the destination is a network in numeric format, the netmask (in /24 style format) is appended. The flags field shows a collection of information about the route stored as binary choices. The individual flags are discussed in more detail in the .Xr route 8 and .Xr route 4 manual pages. .Pp The mapping between letters and flags is: .Bl -column "1" "RTF_BLACKHOLE" "Protocol specific routing flag #1." .It 1 Ta RTF_PROTO1 Ta "Protocol specific routing flag #1." .It 2 Ta RTF_PROTO2 Ta "Protocol specific routing flag #2." .It 3 Ta RTF_PROTO3 Ta "Protocol specific routing flag #3." .It B Ta RTF_BLACKHOLE Ta "Just discard pkts (during updates)." .It b Ta RTF_BROADCAST Ta "Correspond to a local broadcast address." .It C Ta RTF_CLONING Ta "Generate new routes on use." .It c Ta RTF_CLONED Ta "Cloned routes (generated from RTF_CLONING)." .It D Ta RTF_DYNAMIC Ta "Created dynamically (by redirect)." .It G Ta RTF_GATEWAY Ta "Destination requires forwarding by intermediary." .It H Ta RTF_HOST Ta "Host entry (net otherwise)." .It L Ta RTF_LLINFO Ta "Valid protocol to link address translation." .It l Ta RTF_LOCAL Ta "Correspond to a local address." .It M Ta RTF_MODIFIED Ta "Modified dynamically (by redirect)." .It P Ta RTF_MPATH Ta "Multipath route." .It R Ta RTF_REJECT Ta "Host or net unreachable." .It S Ta RTF_STATIC Ta "Manually added." .It T Ta RTF_MPLS Ta "MPLS route." .It U Ta RTF_UP Ta "Route usable." .It X Ta RTF_XRESOLVE Ta "External daemon translates proto to link address." .El .Pp Direct routes are created for each interface attached to the local host; the gateway field for such entries shows the address of the outgoing interface. The refcnt field gives the current number of active uses of the route. Connection oriented protocols normally hold on to a single route for the duration of a connection while connectionless protocols obtain a route while sending to the same destination. The use field provides a count of the number of packets sent using that route. The MTU entry shows the MTU associated with that route. This MTU value is used as the basis for the TCP maximum segment size (MSS). The .Sq L flag appended to the MTU value indicates that the value is locked, and that path MTU discovery is turned off for that route. A .Sq - indicates that the MTU for this route has not been set, and a default TCP maximum segment size will be used. The interface entry indicates the network interface utilized for the route. .Pp When .Nm is invoked with the .Fl w option and a .Ar wait interval argument, it displays a running count of statistics related to network interfaces. An obsolescent version of this option used a numeric parameter with no option, and is currently supported for backward compatibility. This display consists of a column for the primary interface (the first interface found during autoconfiguration) and a column summarizing information for all interfaces. The primary interface may be replaced with another interface with the .Fl I option. The first line of each screen of information contains a summary since the system was last rebooted. Subsequent lines of output show values accumulated over the preceding interval. .Sh SEE ALSO .Xr fstat 1 , .Xr nfsstat 1 , .Xr ps 1 , .Xr systat 1 , .Xr tcpbench 1 , .Xr top 1 , .Xr inet_ntop 3 , .Xr netintro 4 , .Xr route 4 , .Xr hosts 5 , .Xr protocols 5 , .Xr services 5 , .Xr iostat 8 , .Xr portmap 8 , .Xr pstat 8 , .Xr route 8 , .Xr tcpdrop 8 , .Xr trpt 8 , .Xr vmstat 8 .Sh HISTORY The .Nm command appeared in .Bx 4.2 . IPv6 support was added by the WIDE/KAME project. .Sh BUGS The notion of errors is ill-defined.