Allied Telesis AT-S63 - Manual (Page 160)

Chapter 9: Port Mirroring
160 Section I: Basic Features
Port Mirroring Overview
The port mirroring feature allows you to unobtrusively monitor the
traffic being received and transmitted on one or more ports on a switch
by having the traffic copied 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 destination port.
Observe the following guidelines when you create a port mirror:
❑ You can select more than one source port at a time. However, the
more ports you mirror, the less likely 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 that it will not provide an accurate mirror of the
traffic of the six source ports.
❑ The source and destination ports must be located on the same
switch.
❑ You can mirror either the ingress or egress traffic of the source
ports, or both.
Note
When a transceiver is inserted into an uplink slot and a link is
established, that slot becomes a primary uplink port and the
corresponding backup port, 23R or 24R, automatically transitions to
redundant uplink status. Any settings for port mirroring remain
intact when the backup port makes the transition to a redundant
uplink state.