Restrictions; Restrictions On Layer 2 Port Mirroring; Chapter 4 Restrictions - Juniper EX9200 Features Manual

CHAPTER 4

Restrictions

Restrictions on Layer 2 Port Mirroring

Copyright © 2016, Juniper Networks, Inc.
Restrictions on Layer 2 Port Mirroring on page 17
The following restrictions apply to Layer 2 port mirroring:
Only Layer 2 transit data (packets that contain chunks of data transiting the routing
platform or switch as they are forwarded from a source to a destination) can be
mirrored. Layer 2 local data (packets that contain chunks of data that are destined for
or sent by the Routing Engine, such as Layer 2 control packets) are not mirrored.
If you apply a port-mirroring filter to the output of a logical interface, only unicast
packets are mirrored. To mirror broadcast packets, multicast packets, unicast packets
with an unknown destination media access control (MAC) address, or packets with
MAC entry in the destination MAC (DMAC) routing table, apply a filter to the input to
the flood table of a VLAN or virtual private LAN service (VPLS) routing instance.
The mirror destination device should be on a dedicated VLAN and should not participate
in any bridging activity: The mirror destination device should not have a bridge to the
ultimate traffic destination, and the mirror destination device should not send the
mirrored packets back to the source address.
For either the global port-mirroring instance or a named port-mirroring instance, you
can configure only one mirror output interface per port-mirroring instance and packet
address family. If you include more than one
family (ethernet-switching | ccc | vpls) output
statement is overridden.
Layer 2 port-mirroring firewall filtering is not supported for logical systems.
In a Layer 2 port-mirroring firewall filter definition, the filter
or
port-mirror-instance pm-instance-name
in the global instance or named instances of Layer 2 port mirroring, which are configured
under the
[edit forwarding-options port-mirroring]
cannot support Layer 2 port mirroring for logical systems.
For a Layer 2 port mirroring firewall filter in which you implicitly reference Layer 2 port
mirroring properties by including the
of Layer 2 port mirroring are bound to the underlying physical interface, then only the
statement under the
interface
statement, the previous
action-modifier
) relies on port-mirroring properties defined
hierarchy. Therefore, the filter
statement, if multiple named instances
port-mirror
interface
(
port-mirror
term
17