3Com 3C17203 - SuperStack 3 Switch 4400, Implementation Manual

Page: 80 / 153

80 C
HAPTER
7: S
TATUS
M
ONITORING AND
S
TATISTICS
■
It reduces the load on the network and the management
workstation
Traditional network management involves a management workstation
polling network devices at regular intervals to gather statistics and
identify problems or trends. As network sizes and traffic levels grow,
this approach places a strain on the management workstation and
also generates large amounts of traffic.
RMON, however, autonomously looks at the network on behalf of the
management workstation without affecting the characteristics and
performance of the network. RMON reports by exception, which
means that it only informs the management workstation when the
network has entered an abnormal state.
RMON and the
Switch
The RMON support provided by your Switch 4400 is detailed in Table 10 .
Table 10 RMON support supplied by the Switch
RMON group Support supplied by the Switch
Statistics
*
* No Statistics sessions per VLAN supported on Switch 4400 other than VLAN 1.
A new or initialized Switch has one Statistics session per port and
one default Statistics session for VLAN 1.
History †
† No History sessions per VLAN supported on Switch 4400 other than VLAN 1.
A new or initialized Switch has two History sessions per port, and
one default History session for VLAN 1.
These sessions provide the data for the Web interface history
displays:
■
30 second intervals, 120 historical samples stored
■
2 hour intervals, 96 historical samples stored
Alarms A new or initialized Switch has the following alarm(s) defined for
each port:
■
Percentage of errors over one minute
You can modify these alarms using an RMON management
application, but you cannot create or delete them.
You can define up to 200 alarms for the Switch.
For more information about the alarms setup on the Switch, see
“Alarm Events”
on
page 81
and
“The Default Alarm
Settings”
on
page 81
.
Events A new or initialized Switch has Events defined for use with the
default alarm system. See
“The Default Alarm Settings”
on
page 81
for more information.