3Com 3800 - Manual (Page 140)

9-14 C HAPTER 9: S TATUS M ONITORING AND S TATISTICS
An RMON probe, however, autonomously looks at the network on
behalf of the management workstation without affecting the
characteristics and performance of the network. The probe reports by
exception, which means that it only informs the management
workstation when the network has entered an abnormal state.
RMON and the
Switch
RMON requires one probe per LAN segment, and stand-alone RMON
probes have traditionally been expensive. Therefore, 3Com’s approach
has been to build an inexpensive RMON probe into the agent of each
Switch. This allows RMON to be widely deployed around the network
without costing more than traditional network management.
For example, statistics can be related to individual ports and the Switch
can take autonomous actions such as disabling a port (temporarily or
permanently) if errors on that port exceed a predefined threshold. Also,
since a probe must be able to see all traffic, a stand-alone probe must
be attached to a nonsecure port. Implementing RMON in the Switch
means that all ports can have security features enabled.
RMON Features of
the Switch
Table 9-5 details the RMON support provided by the Switch 3800.
Table 9-5 RMON Support Supplied By the Switch 3800
RMON Group Support Supplied by the Switch
Statistics The Switch supports the EtherStats group.
History A new or initialized Switch has two History sessions on each
port:
■
30-second intervals
■
2-hour intervals
The Switch can store a maximum of 50 History sessions.
Alarms The Switch supports up to 50 alarms. You can enter or delete
these alarms using an RMON management application.
Events A new or initialized Switch has events defined for use with
the default alarm system.
SW3800.BK Page 14 Tuesday, May 5, 1998 5:20 PM