NETSTAT(1)						      General Commands Manual							NETSTAT(1)

NAME

       netstat - show network status

SYNOPSIS

       netstat [ -Aan ] [ -f address_family ] [ system ] [ core ]
       netstat [ -himnrs ] [ -f address_family ] [ system ] [ core ]
       netstat [ -n ] [ -I interface ] interval [ system ] [ core ]

DESCRIPTION

       The  netstat  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.	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 an interval specified, netstat will continuously display the information regarding packet traffic on  the  configured  network  inter-
       faces.

       The options have the following meaning:

       -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.

       -h     Show the state of the IMP host table.

       -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).

       -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).   This  option
	      may be used with any of the display formats.

       -s     Show per-protocol statistics.

       -r     Show the routing tables.	When -s is also present, show routing statistics instead.

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

       The arguments, system and core allow substitutes for the defaults ``/vmunix'' and ``/dev/kmem''.

       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.  When known the host and network addresses are  displayed  symbolically  according  to  the  data  bases
       /etc/hosts and /etc/networks, respectively.  If a symbolic name for an address is unknown, or if the -n option is specified, the address is
       printed numerically, according to the address family.  For more information regarding the  Internet  ``dot  format,''  refer  to  inet(3N).
       Unspecified, 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 the state of the route (``U'' if ``up''), whether the route is to a gateway
       (``G''), and whether the route was created dynamically by a redirect (``D'').  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  connec-
       tionless  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 netstat is invoked 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 autoconfiguration) and a column summarizing information
       for all interfaces.  The primary interface may be replaced with another interface with the -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.

SEE ALSO

       iostat(1), vmstat(1), hosts(5), networks(5), protocols(5), services(5), trpt(8C)

BUGS

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

4.2 Berkeley Distribution					    May 8, 1986 							NETSTAT(1)