19-1
Chapter 19: Configuring Port Mirroring
You can mirror traffic from any source port to a target port for real-time analysis. You
can then attach a logic analyzer or RMON probe to the target port and study the
traffic crossing the source port in a completely unobtrusive manner.
Command Usage
• Monitor port speed should match or exceed source port speed, otherwise traffic
may be dropped from the monitor port.
• All mirror sessions have to share the same destination port.
• When mirroring port traffic, the target port must be included in the same VLAN as
the source port when using MSTP (see “Spanning Tree Algorithm Configuration”
on page 22-1).
Command Attributes
• Mirror Sessions – Displays a list of current mirror sessions.
• Source Unit – The unit whose port traffic will be monitored. (Range: Always 1)
• Source Port – The port whose traffic will be monitored. (Range: 1-24/48)
• Type – Allows you to select which traffic to mirror to the target port, Rx (receive),
Tx (transmit), or Both. (Default: Rx)
• Target Unit – The unit whose port will "duplicate" or "mirror" the traffic on the
source port. (Range: Always 1)
• Target Port – The port that will “mirror” the traffic from the source port.
(Range: 1-24/48)
Source
port(s)
Single
target
port