Allied Telesis AT-S79 - Manual (Page 66)

Chapter 6: Port Mirroring
66 Section I: Using the Menus Interface
Port Mirroring Overview
The port mirroring feature allows you to unobtrusively monitor the ingress
and egress traffic on a port on the switch by having the traffic copied to
another switch port. By connecting a network analyzer to the port where
the traffic is being copied to, you can monitor the traffic on the other port
without impacting its performance or speed.
The port whose traffic you want to mirror is called the mirrored port. The
port where the traffic will be copied to is called the mirroring port.
Observe the following guidelines when using this feature:
ˆ You can mirror only one port at a time.
ˆ The mirrored and mirroring ports must be on the same switch.
ˆ This feature copies both the ingress and egress traffic of the mirrored
port.
ˆ The mirroring port cannot be used for normal Ethernet switching.