# CLI-Based Packet Mirroring Overview

The JunosE Software enables you to use CLI commands to configure and manage packet mirroring on specific static IP interfaces, or for a specific user. You use CLI commands to create a secure policy that specifies the analyzer device and how the mirrored traffic is treated.

When you mirror an interface, you can replicate ingress and egress traffic on the interface (traffic entering or exiting the E Series router through that interface). When you mirror a user, you can replicate all traffic to or from the user.

In both interface-specific and user-specific mirroring, the original traffic is forwarded to its intended destination as usual, while the replicated copy of the traffic is forwarded to an analyzer interface on the E Series router. The analyzer interface then directs the mirrored traffic to the specified analyzer device for analysis.

Figure 19 shows the traffic flow for ingress and egress IP interface mirroring.

Figure 19: CLI-Based Interface Mirroring