Configuration manual

RMON
18-4 Configuring Network Monitoring
RMON Design Considerations
The Fixed Switch devices support RMON Packet Capture/Filter Sampling through both the CLI
and MIBs, but with the following constraints:
• RMON Packet Capture/Filter Sampling and Port Mirroring cannot be enabled on the same
interface concurrently.
• You can capture a total of 100 packets on an interface, no more and no less.
– The captured frames will be as close to sequential as the hardware will allow.
– Only one interface can be configured for capturing at a time.
– Once 100 frames have been captured by the hardware, the application will stop without
manual intervention.
• As described in the MIB, the filter is only applied after the frame is captured, thus only a
subset of the frames captured will be available for display.
• There is only one Buffer Control Entry supported.
• Due to the limitations of the hardware, the Buffer Control Entry table will have limits on a few
of its elements:
– MaxOctetsRequested can only be set to the value -1 which indicates the application will
capture as many packets as possible given its restrictions.
– CaptureSliceSize can only be set to 1518.
– The Full Action element can only be set to “lock” since the device does not support
wrapping the capture buffer.
• Due to hardware limitations, the only frame error counted is oversized frames.
• The application does not support Events. Therefore, the following elements of the Channel
Entry Table are not supported: TurnOnEventIndex, TurnOffEventIndex, EventIndex, and
EventStatus.
• There is only one Channel Entry available at a time.
Event Controls the generation and
notification of events from the
device.
Event type, description, last
time event was sent.
show rmon event
set rmon event properties
set rmon event status
clear rmon event
Filter Allows packets to be matched
by a filter definition. These
matched packets form a data
stream or “channel” that may
be captured or may generate
events.
Packets matching the filter
definition.
show rmon channel
set rmon channel
clear rmon channel
show rmon filter
set rmon filter
clear rmon filter
Packet
Capture
Allows packets to be
captured upon a filter match.
Packets matching the filter
definition.
show rmon capture
set rmon capture
clear rmon capture
Table 18-1 RMON Monitoring Group Functions and Commands (continued)
RMON
Group What It Does... What It Monitors... CLI Command(s)