Configuring the Switch

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3
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.
Command Attributes
•Mirror Sessions – Displays a list of current mirror sessions.
•Source Port – The port whose traffic will be monitored.
•Type – Allows you to select which traffic to mirror to the target port, Rx (receive),
Tx (transmit), or Both.
•Target Port – The port that will “duplicate” or “mirror” the traffic on the source port.
Web – Click Port, Mirror Port configuration. Specify the source port, the traffic type to
be mirrored, and the monitor port, then click Add.
Figure 3-48. Mirror Port Configuration
CLI – Use the interface command to select the monitor port, then use the port
monitor command to specify the source port. Note that default mirroring under the
CLI is for both received and transmitted packets.
Console(config)#interface ethernet 1/10 4-125
Console(config-if)#port monitor ethernet 1/13 4-136
Console(config-if)#
Source
port(s)
Single
target
port