Table 4: Configuration Guidelines For Port Mirroring Analyzers - Juniper EX9200 Features Manual

Table 3: Analyzer Terminology (continued)
Term
Statistical analyzer
(Also known as a nondefault
analyzer)
VLAN-based analyzer
Configuration Guidelines for Port Mirroring Analyzers

Table 4: Configuration Guidelines for Port Mirroring Analyzers

Guideline
Number of analyzers that you can enable
concurrently.
Number of interfaces, VLANs, or bridge
domains that you can use as ingress input
to an analyzer.
Copyright © 2016, Juniper Networks, Inc.
Description
You can define a set of mirroring properties that you can explicitly bind to physical ports on
the switch. This set of analyzer properties is known as a statistical analyzer.
An analyzer session whose configuration uses VLANs for both input and output or for either
input or output.
When you configure port mirroring analyzers. we recommend that you follow these
guidelines to ensure optimum benefit. We recommend that you disable mirroring when
you are not using it, and that you select specific interfaces as input to the analyzer rather
than using the keyword option, which enables mirroring on all interfaces. Mirroring
all
only necessary packets reduces any potential performance impact.
You can also limit the amount of mirrored traffic by:
Using statistical sampling
Using a firewall filter
Setting a ratio to select a statistical sample
With local mirroring, traffic from multiple ports is replicated to the analyzer output
interface. If the output interface for an analyzer reaches capacity, packets are dropped.
You must consider whether the traffic being mirrored exceeds the capacity of the analyzer
output interface.
Table 4 on page 7 summarizes further configuration guidelines for analyzers.
Value or Support
Information
64–Default analyzers
2 per FPC–Statistical
analyzer
256
Chapter 1: Understanding Port Mirroring Analyzers
Comment
Statistical analyzers must be bound to an FPC
for mirroring traffic on ports belonging to that
FPC.
NOTE: Default analyzer properties are implicitly
bound on the last (or second to last) instance
on all FPCs in the system. Therefore, when you
explicitly bind a second statistical analyzer on
the FPC, the default analyzer properties are
overridden.
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