In order to prevent traffic congestion and ease the effects of possible bursts, a fabric shaper is implemented on each adapter card. Traffic being switched to a LAG SAP on an access interface goes through fabric shapers that are either in aggregate mode or destination mode. When in destination mode, the multipoint shaper is used to set the rate on all adapter cards. For more information on the modes used in fabric shaping, refer to the 7705 SAR Quality of Service Guide, ‟Configurable Ingress Shaping to Fabric (Access and Network)”.
Even though the multipoint shaper is used to set the fabric shaping rate for traffic switched to a LAG SAP, it is the per-destination unicast counters that are incremented to show the fabric statistics rather than the multipoint counter. Only the fabric statistics of the active port of the LAG are incremented, not the standby port.