Juniper Port Mirror Config

Juniper Port Mirror

Port mirroring is a useful feature that allows you to monitor network traffic by forwarding a copy of network packets from one port to another on your Juniper device. By setting up a port mirror, you can capture network traffic and analyze it with a packet analyzer software or a network analyzer tool. In this guide, we will walk you through the steps to configure port mirroring on a Juniper device.

Steps to Configure Port Mirroring on a Juniper Device

1. Define the port mirror instance:

To define a port mirror instance, use the following command:

set forwarding-options port-mirroring instance {instance-name} input {
    rate 1;
    run {
        port-mirror-input {
            interface {source-interface};
        }
    }
}

• The {instance-name} parameter is the name of the port mirror instance. Choose a name that is easy to remember and descriptive of the traffic being mirrored.
• The rate parameter specifies the sampling rate. In this example, we set it to 1, which means that every packet is mirrored. You can adjust this value according to your needs.
• The {source-interface} parameter is the interface that you want to mirror traffic from. You can specify a physical interface, a VLAN interface, or a VRF interface.

2. Apply the port mirror instance to an output interface:

 

To apply the port mirror instance to an output interface, use the following command:

set interfaces {destination-interface} unit 0 family inet filter {
    input {instance-name};
}

• The {destination-interface} parameter is the interface that you want to send the mirrored traffic to. This can be a physical interface, a VLAN interface, or a VRF interface.
• The {instance-name} parameter is the name of the port mirror instance that you defined in step 1.

Note: You can also apply the port mirror instance to a VLAN or a VRF.

That's it! With these steps, you should be able to configure port mirroring on your Juniper device. You can now monitor network traffic by using a packet analyzer or network analyzer tool.

Conclusion

Port mirroring is a powerful feature that allows you to monitor network traffic without disrupting normal network operations. By configuring port mirroring on your Juniper device, you can gain valuable insights into your network traffic, troubleshoot problems, and optimize network performance.