Configuration Considerations for VLAN-based Rate Limiting

• VLAN-based rate limiting is applicable for ingress traffic only. Egress traffic is blocked by the SLX-OS device.
• There is one policer per ACL, which applies to all the rules for that ACL.
• One thousand and twenty four (1,024) TCAM entries are shared between VLAN rate limiting and DAI features on a first-come, first serve basis.
• Packets drops caused by any action other than ACL rate limiting are included in policing counters.
• Only a permit clause in an ACL rule is subject to rate limit traffic calculations. A deny clause does not result in a policing action.
• Metering is performed at Layer 1 on the packet size as received on the wire (including IPG, Preamble and SOF, ignoring FCS/CRC).
• A policy map can be applied to a physical port, a LAG interface, and a system.
• Multiple class maps with user ACLs can be added in a policy map. However, when a matching ACL clause is found, the device does not evaluate subsequent ACL clauses and rate limits those ACLs.
• A configured rate in bps is rounded up to the next achievable rate.
• The device does not support the specifying of actions to perform on traffic with a color-class priority, such as having packet DSCP priority, traffic class (internal queue assignment), or traffic class (internal queue assignment) set to specific values.
• Statistics display only two colors. Conform includes Green and Yellow packets. Violated includes dropped or a RED packet.
• You cannot delete a policy map that is active on the interface.
• You cannot delete a class map from a policy map when the policy map is active on the interface.
• ( SLX 9640 and SLX 9540 only) Configure CIR and EIR in multiples of 22 kbps. If the value is below 22 kbps, then 22 kbps is programmed in the device.
• If a police map is applied to an interface and no policer attributes are present in that policy map, then ingress and egress packets on that interface are marked as green (conforming).
• If you do not configure EIR, then the Single-rate Three Color scheme (SrTCM) is applied.
• You must configure rate limit threshold values on an interface based on interface speed.
• No validation is performed for user-configured values against interface speed.
• A policy map cannot be bound to an interface if a class map is not associated with that policy map.
• ( SLX 9640 and SLX 9540 only) VLAN rate limiting does not work for VLANs that are carried inside a pseudowire (PW) tunnel.