MSS and LAG Interaction on the 7705 SAR-8 Shelf V2 and 7705 SAR-18

A SAP that uses a LAG can include two or more ports from the same adapter card or two different adapter cards.

In the access egress direction, each port can be assigned a shaper policy for access and can have shaper groups configured with different shaping rates. If a shaper group is not defined, the default shaper group is used. The port egress shaper policy, when configured on a LAG, must be configured on the primary LAG member. This shaper policy is propagated to each of the LAG port members, ensuring that each LAG port member has the same shaper policy.

The following egress MSS restrictions ensure that both active and standby LAG members have the same configuration.

In the ingress direction, there can be two different shaper policies on two different adapter cards for the two port members in a LAG. When assigning a shaper group to an ingress LAG SAP, each shaper policy assigned to the LAG port MDAs must contain that shaper group or the shaper group cannot be assigned. In addition, after a LAG activity switch occurs, the CIR/PIR configuration from the subgroup of the policy of the adapter card of the newly active member will be used.

The following ingress MSS restrictions allow the configuration of shaper groups for LAG SAPs, but the router ignores shaper groups that do not meet the restrictions.