The
snmpnetstat
command symbolically displays the values of various network-related
information retrieved from a remote system using the SNMP protocol.
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.
The second form presents the values of other network-related
information according to the option selected.
Using the third form, with an
interval
specified,
snmpnetstat
will continuously display the information regarding packet
traffic on the configured network interfaces.
The fourth form displays statistics about the named protocol.
The
hostname
specification may be either a host name or an internet address
specified in "dot notation".
The version 1 and version 2c
community
specifies the community name for the transaction with the remote system.
The options have the following meaning:
-a
With the default display,
show the state of all sockets; normally sockets used by
server processes are not shown.
-i
Show the state of all of the interfaces.
-o
Show an abbreviated interface status, giving octets in place of packets.
This is useful when enquiring virtual interfaces (such as Frame-Relay circuits)
on a Cisco router.
-I interface
Show information only about this interface;
used with an
interval
as described below.
-n
Show network addresses as numbers (normally
snmpnetstat
interprets addresses and attempts to display them
symbolically).
This option may be used with any of the display formats.
-p 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 .
A null response typically means that there are no interesting numbers to
report.
The program will complain if
protocol
is unknown or if there is no statistics routine for it.
-s
Show per-protocol statistics.
-r
Show the routing tables.
When
-s
is also present, show routing statistics instead.
The default display, for active sockets, shows the local
and remote addresses, 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
/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''), whether the route was created dynamically
by a redirect (``D''), and whether the route has been modified
by a redirect (``M''). 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 interface entry indicates the network
interface utilized for the route.
When
snmpnetstat
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
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.