External Parent Groups; Example: Configuring Hierarchical Policy Parameters - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - POLICY MANAGEMENT CONFIGURATION GUIDE 2010-10-04 Configuration Manual

JunosE 11.3.x Policy Management Configuration Guide

External Parent Groups

Example: Configuring Hierarchical Policy Parameters

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groups) can point to other external parent groups. Full intra-interface policy hierarchies
for all forwarding layer policies allow classified flows within a policy attachment to share
bandwidth. Bandwidth-sharing between interfaces uses line module global parent group
definitions and interface grouping. However, if you need to share bandwidth between
two or more interfaces, rate-limits must be chained beyond a single attachment.
Policies for interface groups include external parent groups that are implicitly instantiated
during policy attachment based on each unique interface group encountered.
Parent groups act as nonleaf nodes in a hierarchical policy. You can build a hierarchy of
policers using classifier groups as leaf nodes and parent groups as parent nodes within
a policy list. Each classifier group (with or without a rate limit) can point to a single parent
group and that parent group can point to another parent group. To avoid undefined
hierarchies, each node can only point to one other node.
The inter-interface hierarchical model includes references to parent groups that are
defined externally from a policy list. This enables you to define hierarchical nodes outside
the scope of a policy-list attachment. In Global Configuration mode, each external parent
group can have a rate-limit profile defined and have a reference to another external
parent group.
The classifier groups and parent groups within a policy list can point to external parent
groups for all policies that implement hierarchical policies. Each external parent group
reference must also have a policy parameter name.
External parent group names are global. Internal parent group names are local to each
policy configuration. Because both of these name spaces are different, you can configure
overlapping names.
You configure policy parameters in Global Configuration mode. Only hierarchical policy
parameters can have external parent group references. Each parameter has a single
value, depending on the type of parameter. The hierarchical policy parameter can have
a single numeric value or a keyword.
In Interface Configuration mode, you can override the value for a policy parameter for
each interface. The value for a parameter configured in Interface Configuration mode
supersedes the value configured for the parameter in Global Configuration mode. However,
if a parameter is not configured in Interface Configuration mode, the value configured in
Global Configuration mode is used.
Each reference to a policy parameter in a policy is substituted with its value for all
attachments of this policy at the interface. The value can come from the interface or
global configuration for the parameter. Therefore, the value configured for the parameters
referenced in policies can be different for attachments at different interfaces. This enables
you to have an attachment-specific configuration in a policy list that is deferred until the
policy is attached.
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