What Is Port Mirroring - Dell PowerConnect 8024 User Configuration Manual

The RMON agent in the switch supports the following groups:
• Group 1—Statistics. Contains cumulative traffic and error statistics.
• Group 2—History. Generates reports from periodic traffic sampling that
are useful for analyzing trends.
• Group 3 —Alarm. Enables the definition and setting of thresholds for
various counters. Thresholds can be passed in either a rising or falling
direction on existing MIB objects, primarily those in the Statistics group.
An alarm is triggered when a threshold is crossed and the alarm is passed to
the Event group. The Alarm requires the Event Group.
• Group 9 —Event. Controls the actions that are taken when an event
occurs. RMON events occur when:
– A threshold (alarm) is exceeded
– There is a match on certain filters.
NOTE:
The switch supports RMON1.

What is Port Mirroring?

Port mirroring is used to monitor the network traffic that a port sends and
receives. The Port Mirroring feature creates a copy of the traffic that the
source port handles and sends it to a destination port. The source port is the
port that is being monitored. The destination port is monitoring the source
port. The destination port is where you would connect a network protocol
analyzer to learn more about the traffic that is handled by the source port.
A port monitoring session includes one or more source ports that mirror
traffic to a single destination port. The PowerConnect 8024 and 8024F
switches support a single port monitoring session. LAGs (port channels)
cannot be used as the source or destination ports.
For each source port, you can specify whether to mirror ingress traffic (traffic
the port receives, or RX), egress traffic (traffic the port sends, or TX), or both
ingress and egress traffic.
NOTE:
You can create a DiffServ policy class definition that mirrors specific types
of traffic to a destination port. For more information, see "Configuring Differentiated
Services" on page 1075.
Monitoring Switch Traffic
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