Juniper EX9200 Features Manual page 95

Overview
Copyright © 2016, Juniper Networks, Inc.
In this example, you configure a single-rate two-color policer that specifies the bandwidth
limit as a percentage value rather than as an absolute number of bits per second. This
type of policer is called a bandwidth policer. By default, a bandwidth policer enforces a
bandwidth limit based on the line rate of the underlying physical interface. As an option,
you can configure a bandwidth policer to enforce a bandwidth limit based on the
configured shaping rate of the logical interface. To configure this type of bandwidth
policer, called a logical bandwidth policer, you include the
statement in the policer configuration.
To configure a logical interface shaping rate, include the
the
[edit class-of-service interfaces interface interface-name unit logical-unit-number]
hierarchy level. This class-of-service (CoS) configuration statement causes the specified
amount of bandwidth to be allocated to the logical interface.
NOTE: If you configure a policer bandwidth limit as a percentage but a shaping
rate is not configured for the target logical interface, the policer bandwidth
limit is calculated as a percentage of the physical interface media rate, even
if you enable the logical-bandwidth policing feature.
To apply a logical bandwidth policer to a logical interface, you can apply the policer
directly to the logical interface at the protocol family level or (if you only need to rate-limit
filtered packets) you can reference the policer from a stateless firewall filter configured
to operate in interface-specific mode.
Topology
In this example, you configure two logical interfaces on a single Gigabit Ethernet interface
and configure a shaping rate on each logical interface. On logical interface
you allocate 4 Mbps of bandwidth. On logical interface
of bandwidth.
You also configure a logical bandwidth policer with a bandwidth limit of 50 percent and
a maximum burst size of 125,000 bytes, and then you apply the policer to input and
output traffic at the logical units configured on
the policer rate-limits to a bandwidth limit of 2 Mbps (50 percent of the 4 Mbps shaping
rate configured for the logical interface). For logical interface
rate-limits traffic to a bandwidth limit of 1 Mbps (50 percent of the 2 Mbps shaping rate
configured for the logical interface).
If no shaping rate is configured for a target logical interface, the policer rate-limits to a
bandwidth limit calculated as 50 percent of the physical interface media rate. For
example, if you apply a 50 percent bandwidth policer to input or output traffic at a
Gigabit Ethernet logical interface without rate shaping, the policer applies a bandwidth
limit of 500 Mbps (50 percent of 1000 Mbps).
Chapter 8: Bandwidth Policers
logical-bandwidth-policer
shaping-rate bps
, you allocate 2 Mbps
ge-1/3/0.1
ge-1/3/0.0 . For logical interface
, the policer
ge-1/3/0.1
statement at
ge-1/3/0.0 ,
ge-1/3/0.0 ,
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