Allied Telesis AT-S62 - Manual (Page 166)

Chapter 9: Port Mirroring
166 Section I: Basic Operations
Port Mirroring Overview
The port mirroring feature is used to unobtrusively monitor the ingress and
egress traffic on one or more ports by copying the traffic to another port.
By connecting a network analyzer to the port where the traffic is being
copied, you can monitor the traffic on the other ports without impacting
network performance or speed.
The port(s) whose traffic is to be mirrored is called the source port(s). The
port where the traffic is copied to is called the destination port.
Observe the following guidelines when creating a port mirror:
ˆ You can select only one destination port.
ˆ You can select more than one source port. However, the more ports
mirrored, the greater the likelihood the destination port will be 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 it
will not provide an accurate mirror of the traffic of the six source ports.
ˆ You can mirror either the ingress or egress traffic of the source ports,
or both.
ˆ The source and destination ports must be located on the same switch.
ˆ The source ports and the destination port on an AT-8550GB Series
switch must be located within the same port group. The port groups
are:
– Ports 1 to 24 and 49
– Ports 25 to 48 and 50
ˆ To create a mirror port for the Denial of Service defenses, specify only
the destination port for the mirrored traffic. The management software
automatically determines the source ports.