Allied Telesis AT-S79 - Manual (Page 90)

Chapter 8: Port Mirroring
90 Section I: Using the Menus Interface
Port Mirroring Overview
The port mirroring feature allows you to unobtrusively monitor the traffic
received and transmitted on one or more ports by copying the traffic to
another switch port. You can connect a network analyzer to the port where
the traffic is being copied and monitor the traffic on the other ports without
impacting network performance or speed.
The port(s) whose traffic you want to mirror is called the source port(s).
The port where the traffic will be copied to is called the monitor port.
Observe the following guidelines when you create a port mirror:
ˆ You can select more than one source port at a time. However, the
more ports you mirror, the less likely the monitor port is able to handle
all the traffic. For example, if you mirror the traffic of six heavily active
ports, the destination port is likely to drop packets, meaning that it will
not provide an accurate mirror of the traffic of the six source ports.
ˆ The source and monitor ports must be located on the same switch.
ˆ You can mirror either the ingress or egress traffic of the source ports,
or both.