Platform Considerations; Rate Limits - Juniper E320 Configuration Manual

JUNOSe 7.2.x Policy Management Configuration Guide

Platform Considerations

Rate Limits

76 !
Platform Considerations
Rate-limit hierarchies enable rate limits to invoke other rate limits higher in the
hierarchy, which then create different forms of dynamic bandwidth sharing.
Rate-limit hierarchies provide another type of rate limiting that can be used in an IP,
IPv6, MPLS, or L2TP policy; they do not change interface rate limiting. While an IP
rate limit can only be used in an IP policy, the same hierarchical rate limit can be
used in any policy type that allows rate limits. This means that hierarchical rate
limits do not have any type of mark action. Only hierarchical rate limiting can be
used in parent groups, has options for transmit actions, and is color-aware.
Rate-limit profiles are supported on all E-series routers.
For information about the modules supported on E-series routers:
! See the ERX Module Guide for modules supported on ERX-7xx models,
ERX-14xx models, and the ERX-310 router.
! See the E320 Module Guide for modules supported on the E320 router.
To configure rate limiting for interfaces, you first create a rate-limit profile, which is
a set of bandwidth attributes and associated actions. Your router supports two types
of rate-limit profiles—one-rate and two-rate—for IP, IPv6, LT2P, and MPLS Layer 2
transport traffic. You next create a policy list with a rule that has rate limit as the
action and associate a rate-limit profile with this rule.
You configure rate limit profiles from Global Configuration Mode.
NOTE: Commands that you issue in Rate Limit Profile Configuration mode do not
take effect until you exit from that mode.
When packets enter an interface that has a rate-limit profile applied, the router
performs the following:
! Counts the number of bytes (packets) over time
! Categorizes each packet as committed, conformed, or exceeded
! Assigns a transmit, drop, or mark action
NOTE: Mark actions and mask values are supported only on IP, IPv6, and MPLS
rate-limit profiles. hey are not supported on hierarchical rate limits, but are
T
replaced by color-mark profiles.
An additional function of rate limiting is to apply a color code to packets assigned to
each category: green for committed, yellow for conformed, and red for exceeded.
The system uses the color code internally to indicate drop preference when an
outbound interface is congested.