NAME
snmpnetstat - display networking status and configuration information
from a network entity via SNMP
SYNOPSIS
snmpnetstat [common options] [-Ca] [-Cn] AGENT
snmpnetstat [common options] [-Ci] [-Co] [-Cr] [-Cn] [-Cs] AGENT
snmpnetstat [common options] [-Ci] [-Cn] [-CI interface] AGENT
[interval]
snmpnetstat [common options] [-Ca] [-Cn] [-Cs] [-Cp protocol] AGENT
DESCRIPTION
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.
AGENT identifies a target SNMP agent, which is instrumented to monitor
the given objects. At its simplest, the AGENT specification will
consist of a hostname or an IPv4 address. In this situation, the
command will attempt communication with the agent, using UDP/IPv4 to
port 161 of the given target host. See snmpcmd(1) for a full list of
the possible formats for AGENT.
OPTIONS
The options have the following meaning:
common options
Please see snmpcmd(1) for a list of possible values for common options
as well as their descriptions.
-Ca With the default display, show the state of all sockets; normally
sockets used by server processes are not shown.
-Ci Show the state of all of the network interfaces. 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.
-Co 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 router.
-CI interface Show information only about this interface; used with an
interval as described below.
-Cn 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.
-Cp 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.
-Cs Show per-protocol statistics. When used with the -Cr option, show
routing statistics instead.
-Cr Show the routing tables. When -Cs is also present, show per-
protocol routing statistics instead of the routing tables.
When snmpnetstat is invoked with an interval argument, it displays a
running count of statistics related to network interfaces. interval
is the number of seconds between reporting of statistics.
The Active Sockets Display (default)
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 -Cn 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
The interface display provides a table of cumulative statistics
regarding packets transferred, errors, and col- lisions. The network
addresses of the interface and the maximum transmission unit (``mtu'')
are also displayed.
The Routing Table Display
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 pack- ets. 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 inter- face. The interface entry
indicates the network interface utilized for the route.
The Interface Display with an Interval
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 -CI 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 Active Sockets Display for a Single Protocol
When a protocol is specified with the -Cp option, the information
displayed is similar to that in the default display for active sockets,
except the display is limited to the given protocol.
EXAMPLES
Example of using snmpnetstat to display active sockets (default):
% snmpnetstat -v 2c -c public -Ca testhost
Active Internet (tcp) Connections (including servers)
Proto Local Address Foreign Address (state)
tcp *.echo *.* LISTEN
tcp *.discard *.* LISTEN
tcp *.daytime *.* LISTEN
tcp *.chargen *.* LISTEN
tcp *.ftp *.* LISTEN
tcp *.telnet *.* LISTEN
tcp *.smtp *.* LISTEN
...
Active Internet (udp) Connections
Proto Local Address
udp *.echo
udp *.discard
udp *.daytime
udp *.chargen
udp *.time
...
% snmpnetstat -v 2c -c public -Ci testhost
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Queue
eri0 1500 10.6.9/24 testhost 170548881 245601 687976 0 0
lo0 8232 127 localhost 7530982 0 7530982 0 0
Example of using snmpnetstat to show statistics about a specific
protocol:
% snmpnetstat -v 2c -c public -Cp tcp testhost
Active Internet (tcp) Connections
Proto Local Address Foreign Address (state)
tcp *.echo *.* LISTEN
tcp *.discard *.* LISTEN
tcp *.daytime *.* LISTEN
tcp *.chargen *.* LISTEN
tcp *.ftp *.* LISTEN
tcp *.telnet *.* LISTEN
tcp *.smtp *.* LISTEN
...
SEE ALSO
snmpcmd(1), iostat(1), vmstat(1), hosts(5), networks(5), protocols(5),
services(5).
BUGS
The notion of errors is ill-defined.