Monitoring LAG Virtual Interface and Individual LAG Port

Once a LAG is created, monitoring across all ports of the LAG can be configured on the LAG virtual interface. You can configure the device to monitor individual ports in a LAG, including Ethernet or named ports. You can monitor each of the member ports individually. If a new port is added to a LAG and the entire LAG is monitored, the new port will also be mirrored by the same port monitoring traffic across the entire LAG.

Note: You can use only one mirror port for each monitored LAG port.

Complete the following steps to monitor a LAG virtual interface.

Enter the global configuration mode.
```
device# configure terminal
```

Configure port mirroring.

device(config)# mirror-port ethernet 3/1/1

Create a LAG.
```
device(config)# lag blue dynamic id 1
```

Add ports to the LAG.

device(config-lag-blue)# ports ethernet 1/1/1 to 1/1/2 ethernet 2/1/3 to 2/1/4

Configure a LAG virtual interface which allows you to enter the LAG virtual interface mode or multi-LAG virtual interface mode.
```
device(config)# interface lag 1
```

Configure monitoring of both incoming and outgoing traffic on the mirrored port.
```
device(config-lag-if-lg1)# monitor both
```

Enter the exit command to exit from the LAG virtual interface mode.
```
device(config-lag-if-lg1)# exit
```

To view the running configurations, enter the show mirror command.
```
device(config)# show mirror
```

The following example monitors the LAG virtual interface:

device(config)# mirror-port ethernet 3/1/1
device(config)# lag blue dynamic id 1
device(config-lag-blue)# ports ethernet 1/1/1 to 1/1/2 ethernet 2/1/3 to 2/1/4
device(config)# interface lag 1
device(config-lag-if-lg1)# monitor both
device(config-lag-if-lg1)# exit
device(config)# show mirror
Mirror port 3/1/1
Input monitoring : (U1/M1) 1 2
Input monitoring : (U2/M1) 3 4
Input monitoring : (LAG) 1
Output monitoring : (U1/M1) 1 2
Output monitoring : (U2/M1) 3

Example of Monitoring an Individual LAG Port

To monitor traffic on an individual port in a LAG, use the monitor command with the ethe-port-monitored or named-port-monitored parameter to specify the Ethernet port or named port, respectively, that you want to monitor.

The following example configures a static LAG, adds ports, and configures monitoring of the output traffic on Ethernet ports 1/1/47 and 1/1/1:

device(config)# lag blue static id 1
device(config-lag-blue)# ports ethernet 1/1/1 ethernet 1/1/47
device(config-lag-blue)# monitor ethe-port-monitored 1/1/47 ethernet 1/1/1 output

Link Aggregation Group

Monitoring LAG Virtual Interface and Individual LAG Port

Example of Monitoring an Individual LAG Port