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

Port Configuration 3

Source

Single

port(s)

target

 

port

•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. (Range: 1-8)

•Type – Allows you to select which traffic to mirror to the target port, Rx (receive), Tx (transmit), or Both. (Default: Rx)

•Target Port – The port that will "mirror" the traffic from the source port. (Range: 1-8)

Web – Click Port, Mirror Port Configuration. Specify the source port, the traffic type to be mirrored, and the monitor port, then click Add.

Figure 3-61 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 1/7

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Console(config-if)#port monitor ethernet 1/8

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Console(config-if)#

 

 

 

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