netstat(1)netstat(1)NAMEnetstat - show network status
SYNOPSIS
address-family] [system]
address-family] [system [core]]
address-family] protocol] [system]
address-family] protocol] [system [core]]
address-family] interface] [interval] [system]
address-family] interface] [interval] [system [core]]
interface]
protocol]
DESCRIPTION
displays statistics for network interfaces and protocols, as well as
the contents of various network-related data structures. The output
format varies according to the options selected. Some options are
ignored or invalid when used in combination with other options.
Generally, the command takes one of the five forms shown above:
· The first form of the command displays a list of active sock‐
ets for each protocol.
· The second form displays the contents of one of the other
network data structures according to the option selected.
· The third form displays configuration information for each
network interface. It also displays network traffic data on
configured network interfaces, optionally updated at each
interval, measured in seconds.
· The fourth form displays current network interface or proto‐
col statistics and zeroes them out.
· The last form deletes all bookkeeping files created by
Options are interpreted as follows:
Show the state of all sockets, including passive sockets
used by server processes. When is used with‐
out any options only active sockets are shown.
This option does not show the state of X.25
programmatic access sockets. The option is
ignored if the or interval option is speci‐
fied.
Deletes all the bookkeeping files created by
The bookkeeping files are located at
Note: If the bookkeeping files are deleted
with the option, then defaults to reporting
statistics since boot time for the option.
Show statistics or address control block for only the specified
address-family. The following address fami‐
lies are recognized: for for and for This
option with applies to the and options. This
option with or applies to the and options.
Show multicast information for network interfaces.
Only the address family is recognized by this
option. This option may be combined with the
option to display both kinds of information.
The option is ignored if the option is speci‐
fied.
Show the state of network interfaces.
Only the interfaces that have been configured
with an IP address or the option using the
command are shown. The output includes both
the primary and logical interfaces. (See
ifconfig(1M)).
The counts for the Ipkts and Opkts fields are
for IP packets only.
This option is ignored if the option is speci‐
fied. By default, when the option is not
specified, shows the state of interfaces con‐
figured with either IPv4 or IPv6 addresses.
An exception is when the user has not config‐
ured any IPv6 address on any interface, does
not display the state of the IPv6 loopback
interface.
Show information about the specified interface only.
This option applies to the and options.
Show the multicast routing tables.
When is used with the option, displays multi‐
cast routing statistics instead. This option
is ignored if the option is specified.
Show network addresses as numbers.
Normally, interprets addresses and attempts to
display them symbolically. This option
applies to the and options.
Show statistics for the specified protocol.
The following protocols are recognized: and
Show the routing tables.
When is used with the option, also displays
the network masks in the route entries. This
option is ignored if the or interval option is
specified and is invalid if the option is
specified.
Show statistics for all protocols.
When this option is used with the option, dis‐
plays multicast routing statistics instead.
This option is ignored if the or interval
option is specified and is invalid if the
option is specified.
Show additional routing information.
When is used with the option, also displays
the network masks in the route entries.
With SCTP, because there may be multiple
addresses involved in a SCTP socket endpoint,
the command displays all local and remote
addresses of a SCTP socket.
Note: SCTP is available only if the optional
SCTP bundle is installed.
Show the output in wide format. This option displays
all the fields in the output with their maxi‐
mum resolution in a single line. Thus, the
output can be worked upon with text-processing
tools. This option works only with the option
and will be ignored when used with any other
option.
Display the current network interface statistics or protocol
statistics, then set them to zero. This
option must be specified with either the
interface option, or option, or the protocol
option. This option supports the following
protocols only: and
In addition, you must be superuser to use this
option.
Note: If the statistics of an interface is
zeroed using the option and the same interface
is reconfigured, then the statistics reported
with option for that interface will be incon‐
sistent. So, after an interface is reconfig‐
ured, option should be used only after zeroing
the statistics again using option.
Display statistics since they were last zeroed. By default,
displays statistics since the system was last
booted. Use this option with the and options
only.
For the option, the display of Ipkts and Opkts on a host system depends
on the following scenarios.
1. If the user configures virtual LANs on an interface (say lanX), with
the IP addresses of the virtual LANs (say lanX:1, lanX:2, and so on)
belonging to the same subnet as that of the primary interface
(lanX:0), then the Opkts field of the primary interface (lanX:0)
will always be incremented unless the destination address is one of
the local addresses on the host.
2. If the user configures same subnet IP addresses on different primary
interfaces (lanX, lanY and so on), then Opkts of the interface which
was last configured will be incremented.
If the user wants Opkts of the exact interface to be incremented, then
he needs to use the tunable with suitable values
The system argument allows substitution for the default value On PA-
RISC systems only, the core argument allows substitution for the
default value
If no options are specified, displays the status of only active sock‐
ets. The display of active and passive sockets status shows the local
and remote addresses, send and receive queue sizes (in bytes), proto‐
col, and the internal state of the protocol.
Note: The send and receive queue size displayed is usually zero. These
fields are displayed only for backward compatibility purposes.
Address formats are in two forms: or if the host portion of a socket
address is zero. When known, the host and network addresses are dis‐
played symbolically by using and respectively (see gethostent(3N) and
getnetent(3N)) for IPv4, and for IPv6 (see getaddrinfo(3N)). If a sym‐
bolic name for an address is unknown, the address is displayed numeri‐
cally according to the address family. For more information regarding
the Internet "dot format" for IPv4 addresses, refer to inet(3N). For
more information regarding the Internet "colon format" for IPv6
addresses, refer to inet6(3N). Unspecified or "wildcard" addresses and
ports appear as an asterisk
The interface display provides a table of cumulative statistics regard‐
ing packets transferred, both inbound and outbound. The network
addresses of the interface and the maximum transmission unit (MTU) are
also displayed. When the interval argument is specified, displays a
running count of statistics related to network interfaces. This dis‐
play consists of a column for the first interface found during auto-
configuration and a column summarizing information for all interfaces.
To display a running count of statistics for a specific interface, use
the 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.
The routing table display indicates the available routes and their sta‐
tus. Each route consists of a destination host or network, a netmask
and a gateway to use in forwarding packets. The field shows whether
the route is up whether the route is to a gateway or whether the route
is a host or network route (with or without
The field shows the mask to be applied to the destination IP address of
an IP packet to be forwarded. The result will be compared with the
destination address in the route entry. If they are the same, then the
route is one of the candidates for routing this IP packet. If there
are several candidate routes, then the route with the longest field
(contiguous 1's starting from the left-most bit position) will be cho‐
sen. (see routing(7).)
The field shows the address of the immediate gateway for reaching the
destination. It can be the address of the outgoing interface if the
destination is on a directly connected network.
The field identifies which network interface is used for the route.
The field displays the path maximum transmission unit (PMTU). If the
route is created with a static PMTU value (see route(1M)), the corre‐
sponding PMTU value permanently overrides the interface MTU. Other‐
wise, the PMTU value is the same as the MTU of the network interface
used for the route.
The field is for IPv6 only. Its format is similar to the CIDR notation
in IPv4. The prefix is an integer between 0 and 128 inclusive. It
specifies how many of the leftmost contiguous bits of the address com‐
prise the prefix. A host route has a prefix of 128. A default route
has a prefix of 0 (see route(1M)). The prefix is also used in select‐
ing a route to forward an IPv6 packet.
DEPENDENCIES
X.25
option does not list X.25 programmatic access information.
AUTHOR
was developed by HP and the University of California, Berkeley.
SEE ALSOifconfig(1M), nwmgr(1M), route(1M), inet(3N), inet6(3N), gethos‐
tent(3N), getnetent(3N), getaddrinfo(3N), hosts(4), networks(4), proto‐
cols(4), services(4), route(7P), sctp(7), routing(7).
netstat(1)
