8 Product Overview ELS100-24TX
RMONRMON (Remote Monitoring) is a facility used to manage networks
remotely while providing mu lti-vendo r inte roperabi lity b etween mo nitoring
devices and management stations. RMON is defined by an SNMP MIB.
This MIB is divided into nine different groups, each gathering specific
statistical information or performing a specific function. RMON-capable
devices gather network traffic data and then store them locally until
downloaded to an SNMP management station.
The ELS100-24TX supports four of the nine gro ups of RMON define d for
Ethernet networks on a per port basis. Specifically, these are:
•Statistics: a function that maintains counts of network traffic sta tistics
such as number of packets, broadcasts, collisions, errors, and
distribution of packet sizes.
•History: a function which collects historical statistics based on user-
defined sampling intervals. The statistical information collected is the
same as the Statistics group, except on a time stamped basis.
•Alarm: a function that allows manager s to set alarm thresh olds based
on traffic statistics. Alarms trigger other actions through the Event
group.
•Event: a function that operates with the Alarm group to define an
action that will be taken when an alarm condition occurs. The event
may write a log entry and/or send a trap message.
RMON Statistics group information is displayed on the Port Statistics
Screen in the console menus. Addi tional RMON functionality is availa bl e
via SNMP.
Port MirroringThe ELS100-24TX switch includes the ability to mirror the traffic being
switched on any port for purposes of network traffic analysis and
connection integrity. When th is f eat ur e i s e nab l ed, a protocol analyzer or
RMON probe is connected to any port in a group of eight. This port is
configured to mirror the traffic from any other port in the same group of
ports. The groupings are ports 1-8, 9-16 and 17-24. You can only mirror
one port to another port at one time. Port mirror ing occurs at the sam e
speed configured for the port (10Mbps-to-10Mbps or 100Mbps-to-
100Mbps). Port mirror ing is configurable i n t he Switch Configurat ion
Menu using the console menus or via SNMP.
Auto-negotiationAuto-negotiation is a process that permits the switch to automatically
select the operational modes o f it s por ts . U pon fi r st b ei ng c on nected, the
switch detects the speed of the network the port is connected to, either
10Mbps or 100Mbps, and the type of communication setting, half or full
duplex. The port is then automatically set by the switch to operate in the
proper mode, without user intervention. It is not req uired th at the ne twork
device being connected to the switch supports auto-negotiation as the