BigIron RX Series Configuration Guide 23753-1002253-01Chapter8Link AggregationLink aggregation overviewThis chapter describes how to configure Link Aggregation Groups (LAG). You can use a singleinterface to configure any of the following LAG types:• Static LAGs – These trunk groups are manually-configured aggregate links containing multipleports.• Dynamic LAGs – This LAG type uses the Link Aggregation Control Protocol (LACP), to maintainaggregate links over multiple port. LACP PDUs are exchanged between ports on eachswitchswitch to determine if the connection is still active. The LAG then shuts down portswhose connection is no longer active.• Keep Alive LAGs – In a Keep Alive LAG a single connection between a single port on 2 BigIronRX switches is established. In a keep alive LAG, LACP PDUs are exchanged between the 2 portsto determine if the connection between the switches is still active. If it is determined that theconnection is no longer active, the ports are blocked.NOTENo trunk is created for “Keep Alive” LAGsLAG formation rulesGiven below are the LAG formation rules:• You cannot configure a port concurrently as a member of a static, dynamic, or keep-alive LAG• Any number or combination of ports between 1 and 8 within the same device can be used toconfigure a LAG. The maximum number of LAG ports is checked when adding ports to a LAG.• All ports configured in a LAG must be of equal bandwidth. For example all 10 G ports.• All ports configured in a LAG must be configured with the same port attributes.• Trunk formation rules are checked when a static or dynamic LAG is deployed.• A LAG must have its primary port selected before it can be deployed.• All ports configured in a LAG must be configured in the same VLAN.• All ports must have the same PBR configuration before deployment, during deployment theconfiguration on the primary port is replicated to all ports and on undeployment each portinherits the same PBR configuration.• VLAN and inner-VLAN translation.The trunk is rejected if any LAG port has VLAN or inner-VLAN translation configured• Layer 2 requirements.The trunk is rejected if the trunk ports:• do not have the same untagged VLAN component.
