CANOGA PERKINS CanogaOS Configuration Guide - Manual (Page 338)

CanogaOS Configuration Guide
Proprietary & Confidential Canoga Perkins Metro Ethernet Switches Page 338 of 350
46 Configuring Mirror
This chapter describes how to configure mirror on your switch.
46.1.1 References
46.1.2 Terminology
The following describes concepts and terminology associated with mirror configuration.
Mirror Session
A mirror session is an association of a destination port with source ports and source VLANs.
You configure mirror sessions by using parameters that specify the source of network traffic to
monitor. Both switched and routed ports can be configured as mirror sources and destinations.
You can configure up to 4 mirror sessions.
Mirror sessions do not interfere with the normal operation of the switch. However, an
oversubscribed mirror destination, for example, a 10-Mbps port monitoring a 100-Mbps port,
results in dropped or lost packets.
You can configure mirror sessions on disabled ports; however, a mirror session does not become
active unless you enable the destination port and at least one source port or VLAN for that
session.
A mirror session remains inactive after system power-on until the destination port is operational.
Traffic Types
Mirror sessions include these traffic types:
z
Receive (Rx) mirror—The goal of receive (or ingress) mirror is to monitor as much as
possible packets received by the source interface or VLAN before any modification or
processing is performed by the switch. A copy of each packet received (except these packets:
BPDU, LACPDU, BMGPDU, packets have been discarded by IP-MAC binding check, CRC
error packets) by the source is sent to the destination port for that mirror session. You can
monitor a series or range of ingress ports or VLANs in a mirror session.
Packets that are modified because of routing are copied without modification; that is, the
original packet is copied. Packets that are modified because of quality of service (QoS)—for
example, modified Differentiated Services Code Point (DSCP)—are copied with
modification. Packets that are modified because of VLAN translation or VLAN classification
is copied with the modification.
Some features that can cause a packet to be dropped during receive processing have no effect
on mirror, the destination port can receive a copy of the packet even if the actual incoming