Dell PowerSwitch S5212F-ON EMC SmartFabric OS10 User Guide Release 10.5.0 - Page 1168

In the S4200-ON Series platform, configure separate thresholds for ECN capable traffic (ECT). If you enable ECN, ECT is marked based on the configured ECN threshold and non-ECT drops based on the WRED thresholds. Storm control Traffic storms created by packet flooding or other reasons may degrade the performance of the network. The storm control feature allows you to control unknown unicast, multicast, and broadcast traffic on L2 and L3 physical interfaces. OS10 devices monitor the current level of the traffic rate at fixed intervals, compares the traffic rate with the configured levels, and drops excess traffic. By default, storm control is disabled on all interfaces. Enable storm control using the storm-control { broadcast | multicast | unknown-unicast } rate-in-pps command in INTERFACE mode. NOTE: This feature is not supported on the Z9332F-ON platform. • Enable broadcast storm control with a rate of 1000 packets per second (pps) on Ethernet 1/1/1. OS10(conf-if-eth1/1/1)# storm-control broadcast 1000 RoCE for faster access and lossless connectivity Remote Direct Memory Access (RDMA) enables memory transfers between two computers in a network without involving the CPU of either computer. RDMA networks provide high bandwidth and low latency without appreciable CPU overhead for improved application performance, storage and data center utilization, and simplified network management. RDMA was traditionally supported only in an InfiniBand environment. Currently, RDMA over Converged Ethernet (RoCE) is also implemented in data centers that use Ethernet or a mixedprotocol environment. OS10 devices support RoCE v1 and RoCE v2 protocols. • RoCE v1 - An Ethernet layer protocol that allows for communication between two hosts that are in the same Ethernet broadcast domain. • RoCE v2 - An Internet layer protocol that allows RoCE v2 packets to be routed, called Routable RoCE (RRoCE). To enable RoCE, configure the QoS service policy on the switch in ingress and egress directions on all the interfaces. For more information about this configuration, see Configure RoCE on the switch. Configure RoCE on the switch To configure RoCE, classify the ingress and egress traffic as lossy and lossless traffic. Based on the classification, assign the ECN threshold and bandwidth for the respective queues. For RoCEv1, ECN threshold configuration is not required. Configuration notes • Use the trust-map or policy-map CLI commands to configure dot1p and DSCP traffic-class markings. For RoCEv2, classification is based only on DSCP. • Use the qos-map CLI command to apply the traffic class to queues. • Use the network-type policy-map to classify any of the priority values as lossless and fine-tune the respective buffer value depending on traffic congestion. • Adjust the ECN threshold based on the traffic pattern. • Use the queuing-type policy-map to modify the bandwidth allocation for lossy and lossless queues. • If you are using RoCEv1, only bandwidth allocation is required. ECN and ECN queue association are not required. • To ensure lossless traffic flow, configure PFC on all lossless interfaces. The following example describes the steps to configure RoCE on the switch. This configuration example uses priority 3 for RoCE. 1. Enter CONFIGURATION mode. OS10# configure terminal OS10 (config)# 1168 Quality of service