Dell Converged Enhanced Ethernet Administrator’s Guide 753-1002116-01Layer 2 Ethernet overview 1- Multicast output queuing—A typical multicast output queuing example is where severalports carry multicast inbound traffic. Each port has a different priority setting. Traffic fromall ports is switched to the same outbound port. If the inbound ports have varying trafficrates, some outbound priority groups will be congested while others remain uncongested.The traffic rate of the traffic streams that are uncongested remains high. The outboundports should carry some multicast frames from all the inbound ports.• Scheduling—A typical example of scheduling policy (using SP0 and SP1 modes) is where ports0 through 7 carry inbound traffic, each port has a unique priority level, port 0 has priority 0,port 1 has priority 1, and so on. All traffic is switched to the same outbound port. In SP0 mode,all ports have DWRR scheduling; therefore, the frames-per-second (FPS) on all ports shouldcorrespond to the DWRR settings. In SP1 mode, priority 7 traffic uses SP; therefore, priority 7can achieve a higher FPS. Frames from input ports with the same priority level should bescheduled in a round robin manner to the output port.When setting the scheduling policy, each priority group that is using DWRR scheduling can beset to use a percentage of the total bandwidth by setting the PG_Percentage parameter.For detailed information on configuring QoS, see “Configuring QoS using the CEE CLI” on page 93.Access controlAccess Control Lists (ACLs) are used for Layer 2 switching security. Standard ACLs inspect thesource address for the inbound ports. Extended ACLs provide filtering by source and destinationaddresses and protocol. ACLs can be applied to the CEE ports or to VLANs.ACLs function as follows:• A standard Ethernet ACL configured on a physical port is used to permit or deny frames basedon the source MAC address. The default is to permit all frames.• An extended Ethernet ACL configured on a physical port is used to permit or deny framesbased on the source MAC address, destination MAC address, and EtherType. The default is topermit all frames.• A standard Ethernet ACL configured on a LAG virtual port is used to permit or deny framesbased on the source MAC address. The default is to permit all frames. LAG ACLs apply to allports in the LAG.• An extended Ethernet ACL configured on a LAG virtual port is used to permit or deny framesbased on the source MAC address, destination MAC address, and EtherType. The default is topermit all frames. LAG ACLs apply to all ports in the LAG.• A standard Ethernet ACL configured on a VLAN is used to permit or deny frames based on thesource MAC address. The default is to permit all frames. VLAN ACLs apply to the Switch VerticalInterface (SVI) for the VLAN.• An extended Ethernet ACL configured on a VLAN is used to permit or deny frames based on thesource MAC address, destination MAC address, and EtherType. The default is to permit allframes. VLAN ACLs apply to the Switch Vertical Interface (SVI) for the VLAN.For detailed information on configuring ACLs, see “Configuring ACLs using the CEE CLI” on page 87.Access GatewayAll ports on the switch come from the factory set to Access Gateway mode, with the default AccessGateway mapping. See the “Access Gateway Administrator’s Guide” for full details.
