.\" Copyright (c) 1983, 1990, 1992, 1993
.\" The Regents of the University of California. All rights reserved.
.\" %sccs.include.redist.roff%
.\" @(#)netstat.1 8.6 (Berkeley) %G%
.Op Fl f Ar address_family
.Op Fl f Ar address_family
command symbolically displays the contents of various network-related
There are a number of output formats,
depending on the options for the information presented.
The first form of the command displays a list of active sockets for
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
will continuously display the information regarding packet
traffic on the configured network interfaces.
The fourth form displays statistics about the named protocol.
The options have the following meaning:
With the default display,
show the address of any protocol control blocks associated with sockets; used
With the default display,
show the state of all sockets; normally sockets used by
server processes are not shown.
With either interface display (option
or an interval, as described below),
show the number of dropped packets.
Show information related to multicast (group address) routing.
By default, show the IP Multicast virtual-interface and routing tables.
option is also present, show multicast routing statistics.
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).
options 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.
Show information about the specified interface;
interval as described below.
Extract values associated with the name list from the specified core
Show statistics recorded by the memory management routines
(the network manages a private pool of memory buffers).
Extract the name list from the specified system instead of the default
Show network addresses as numbers (normally
interprets addresses and attempts to display them
This option may be used with any of the display formats.
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
A null response typically means that there are no interesting numbers to
The program will complain if
is unknown or if there is no statistics routine for it.
Show per-protocol statistics.
If this option is repeated, counters with a value of zero are suppressed.
is also present, show routing statistics instead.
.It Fl f Ar address_family
Limit statistics or address control block reports to those
The following address families
Show network interface statistics at intervals of
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.
Address formats are of the form ``host.port'' or ``network.port''
if a socket's address specifies a network but no specific host address.
When known the host and network addresses are displayed symbolically
according to the data bases
respectively. If a symbolic name for an address is unknown, or if
option is specified, the address is printed numerically, according
For more information regarding
the Internet ``dot format,''
or ``wildcard'', addresses and ports appear as ``*''.
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.
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. The flags field shows
a collection of information about the route stored as
binary choices. The individual flags are discussed in more
The mapping between letters and flags is:
G RTF_GATEWAY Destination requires forwarding by intermediary
H RTF_HOST Host entry (net otherwise)
R RTF_REJECT Host or net unreachable
D RTF_DYNAMIC Created dynamically (by redirect)
M RTF_MODIFIED Modified dynamically (by redirect)
C RTF_CLONING Generate new routes on use
X RTF_XRESOLVE External daemon translates proto to link address
L RTF_LLINFO Valid protocol to link address translation.
S RTF_STATIC Manually added
B RTF_BLACKHOLE Just discard pkts (during updates)
1 RTF_PROTO2 Protocol specific routing flag #1
2 RTF_PROTO1 Protocol specific routing flag #2
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
The use field provides a count of the number of packets
sent using that route. The interface entry indicates the network
interface utilized for the route.
interval argument, it displays a running count of statistics related to
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
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.
.\" .Bl -tag -width /dev/kmem -compact
.\" default kernel namelist
The notion of errors is ill-defined.
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