NETSTAT(1)                           BSD                            NETSTAT(1)



NAME
     netstat - show network status

SYNOPSIS
     netstat [ -Aang ] [ -f address_family ]
     netstat [ -himnrstT ] [ -f address_family ]
     netstat [ -n ] [ -I interface ] interval

DESCRIPTION
     The netstat command symbolically displays the contents of various
     network-related data structures.  You can specify one of a number of
     output formats.  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.
     The third form, with an interval specified, continuously displays the
     information regarding packet traffic on the configured network
     interfaces.

     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.  It displays the host and network addresses,
     when known, symbolically, according to the databases /etc/hosts and
     /etc/networks, respectively.  If a symbolic name for an address is
     unknown, or if you specify the -n option, netstat displays the address
     numerically, according to the address family.  For more information
     regarding the Internet "dot format," refer to inet(3N). netstat displays
     unspecified, or "wildcard", addresses and ports an asterisk (*).

     The interface display provides a table of cumulative statistics regarding
     packets transferred, errors, and collisions.  It also shows the network
     addresses of the interface and the maximum transmission unit (mtu).

     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 the following:

     ⊕  The state of the route (U if "up")

     ⊕  Whether the route is to a gateway (G)

     ⊕  Whether the route was created dynamically by a redirect (D)

     ⊕  Whether the route has priority (P)

     ⊕  Whether the route is a static (S) route added with route

     ⊕  Whether the route has been marked for deletion (X).

     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
     interface entry indicates the network interface utilized for the route.

     When you invoke netstat with an interval argument, it displays a running
     count of statistics related to network interfaces.  This display consists
     of a column for the primary interface (the first interface found during
     auto-configuration) and a column summarizing information for all
     interfaces.  Use the -I option to replace the primary interface with
     another interface.  The first line of each screen of information contains
     a summary since the system was last rebooted.  Subsequent output lines
     show values accumulated over the preceding interval.

OPTIONS
     -A        With the default display, show the address of any protocol-
               control blocks associated with sockets; used for debugging.

     -a        With the default display, show the state of all sockets;
               normally sockets used by server processes are not shown.

     -g        With the default display, show the first gateway used.

     -h        Show the state of the IMP host table.  Status flags show the
               gateway entry (G), in use (U), a temporary entry (T).

     -i        Show the state of interfaces that were auto-configured (netstat
               does not show interfaces statically configured into a system,
               but not located at boot time).

     -I interface
               Show information only about this interface; used with an
               interval as described below.

     -m        Show statistics recorded by the memory-management routines (the
               network manages a private pool of memory buffers).

     -n        Show network addresses as numbers (normally netstat interprets
               addresses and attempts to display them symbolically).  You can
               use this option with any of the display formats.

     -s        Show per-protocol and routing statistics.

     -r        Show the routing tables.

     -t        When used with the -i option, show timer column.

     -T        Show all possible status information.

     -f address_family
               Limit statistics or address-control-block reports to those of
               the specified address family.  The following address families
               are recognized:  inet, for AF_INET; ns, for AF_NS; and unix,
               for AF_UNIX.

BUGS
     The notion of errors is ill-defined.  Collisions mean something else for
     the IMP.

SEE ALSO
     hosts(5), networks(5), protocols(5), services(5), trpt(8C)