Manual Pages for UNIX Darwin command on man netstat

NETSTAT(1) BSD General Commands Manual NETSTAT(1)

NAME

nneettssttaatt - show network status

SYNOPSIS

nneettssttaatt [-AAaaLLllnnWW] [-ff addressfamily | -pp protocol] [-MM core] [-NN system]

nneettssttaatt [-ggiillnnss] [-ff addressfamily] [-MM core] [-NN system]

nneettssttaatt -ii | -II interface [-ww wait] [-aabbddggtt] [-MM core] [-NN system]

nneettssttaatt -ss [-ss] [-ff addressfamily | -pp protocol] [-MM core] [-NN system]

nneettssttaatt -ii | -II interface -ss [-ff addressfamily | -pp protocol] [-MM core]

[-NN system]

nneettssttaatt -mm [-MM core] [-NN system]

nneettssttaatt -rr [-AAaallnn] [-ff addressfamily] [-MM core] [-NN system]

nneettssttaatt -rrss [-ss] [-MM core] [-NN system]

DESCRIPTION

The nneettssttaatt command symbolically displays the contents of various net-

work-related data structures. 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 each protocol. The

second form presents the contents of one of the other network data struc-

tures according to the option selected. Using the third form, with a wait interval specified, nneettssttaatt will continuously display the information regarding packet traffic on the configured network interfaces. The fourth form displays statistics for the specified protocol or address

family. The fifth form displays per-interface statistics for the speci-

fied protocol or address family. The sixth form displays mbuf(9) statis-

tics. The seventh form displays routing table for the specified address family. The eighth form displays routing statistics. The options have the following meaning:

-AA With the default display, show the address of any protocol control

blocks associated with sockets; used for debugging.

-aa With the default display, show the state of all sockets; normally

sockets used by server processes are not shown. With the routing

table display (option -rr, as described below), show protocol-cloned

routes (routes generated by a RTFPRCLONING parent route); normally these routes are not shown.

-bb With the interface display (option -ii, as described below), show

the number of bytes in and out.

-dd With either interface display (option -ii or an interval, as

described below), show the number of dropped packets.

-ff addressfamily

Limit statistics or address control block reports to those of the

specified address family. The following address families are rec-

ognized: inet, for AFINET, inet6, for AFINET6 and unix, for AFUNIX.

-gg Show information related to multicast (group address) routing. By

default, show the IP Multicast virtual-interface and routing

tables. If the -ss option is also present, show multicast routing

statistics.

-II interface

Show information about the specified interface; used with a wait

interval as described below. If the -ss option is present, show

per-interface protocol statistics on the interface for the speci-

fied addressfamily or protocol, or for all protocol families.

-ii 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). If the -aa options is also present, mul-

ticast 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. If the -ss option is present, show per-

interface statistics on all interfaces for the specified addressfamily or protocol, or for all protocol families.

-LL Show the size of the various listen queues. The first count shows

the number of unaccepted connections. The second count shows the amount of unaccepted incomplete connections. The third count is the maximum number of queued connections.

-ll Print full IPv6 address.

-MM Extract values associated with the name list from the specified

core instead of the default /dev/kmem.

-mm Show statistics recorded by the memory management routines (the

network manages a private pool of memory buffers).

-NN Extract the name list from the specified system instead of the

default /kernel.

-nn Show network addresses as numbers (normally nneettssttaatt interprets

addresses and attempts to display them symbolically). This option may be used with any of the display formats.

-pp protocol

Show statistics about 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 /etc/protocols. The special protocol name

``bdg'' is used to show bridging statistics. A null response typi-

cally means that there are no interesting numbers to report. The

program will complain if protocol is unknown or if there is no sta-

tistics routine for it.

-rr Show the routing tables. Use with -aa to show protocol-cloned

routes. When -ss is also present, show routing statistics instead.

When -ll is also present, nneettssttaatt assumes more columns are there and

the maximum transmission unit (``mtu'') are also displayed.

-ss Show per-protocol statistics. If this option is repeated, counters

with a value of zero are suppressed.

-WW In certain displays, avoid truncating addresses even if this causes

some fields to overflow.

-ww wait

Show network interface statistics at intervals of wait seconds. OOUUTTPPUUTT 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 net-

work but no specific host address. If known, the host and network addresses are displayed symbolically according to the databases /etc/hosts and /etc/networks, respectively. If a symbolic name for an

address is unknown, or if the -nn option is specified, the address is

printed numerically, according to the address family. For more informa-

tion regarding the Internet ``dot format'', refer to inet(3)). Unspeci-

fied, or ``wildcard'', addresses and ports appear as ``*''. Internet domain socket states: CLOSED: The socket is not in use. LISTEN: The socket is listening for incoming connections. Unconnected

listening sockets like these are only displayed when using the -a option.

SYNSENT: The socket is actively trying to establish a connection to a remote peer. SYNRCVD: The socket has passively received a connection request from a remote peer. ESTABLISHED: The socket has an established connection between a local application and a remote peer. CLOSEWAIT: The socket connection has been closed by the remote peer, and the system is waiting for the local application to close its half of the connection. LASTACK: The socket connection has been closed by the remote peer, the local application has closed its half of the connection, and the system is waiting for the remote peer to acknowledge the close. FINWAIT1: The socket connection has been closed by the local application, the remote peer has not yet acknowledged the close, and the system is waiting for it to close its half of the connection. FINWAIT2: The socket connection has been closed by the local application, the remote peer has acknowledged the close, and the system is waiting for it to close its half of the connection. CLOSING: The socket connection has been closed by the local application and the remote peer simultaneously, and the remote peer has not yet acknowledged the close attempt of the local application. TIMEWAIT: The socket connection has been closed by the local application, the remote peer has closed its half of the connection, and the system is waiting to be sure that the remote peer received the last acknowledgement. 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 dis-

played.

The routing table display indicates the available routes and their sta-

tus. 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 detail in the route(8) and route(4) manual pages. The mapping between letters and flags is:

1 RTFPROTO1 Protocol specific routing flag #1

2 RTFPROTO2 Protocol specific routing flag #2

3 RTFPROTO3 Protocol specific routing flag #3

B RTFBLACKHOLE Just discard packets (during updates) b RTFBROADCAST The route represents a broadcast address C RTFCLONING Generate new routes on use

c RTFPRCLONING Protocol-specified generate new routes on use

D RTFDYNAMIC Created dynamically (by redirect) G RTFGATEWAY Destination requires forwarding by intermediary H RTFHOST Host entry (net otherwise) L RTFLLINFO Valid protocol to link address translation M RTFMODIFIED Modified dynamically (by redirect) R RTFREJECT Host or net unreachable S RTFSTATIC Manually added U RTFUP Route usable W RTFWASCLONED Route was generated as a result of cloning X RTFXRESOLVE External daemon translates proto to link address 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 pro-

vides a count of the number of packets sent using that route. The inter-

face entry indicates the network interface utilized for the route.

When nneettssttaatt is invoked with the -ww option and a wait interval argument,

it displays a running count of statistics related to network interfaces. An obsolete version of this option used a numeric parameter with no option, and is currently supported for backward compatibility. By

default, this display summarizes information for all interfaces. Infor-

mation for a specific interface may be displayed with the -II option.

BUGS

The notion of errors is ill-defined.

Darwin June 15, 2001 Darwin