Dell DR4100 Best Practices Manual

Also see for PowerVault DR4100: Administrator's guide Reference guide Release note Manual Manual

Contents

17 DR4100 Best Practice Guide | April 20146.2 Network Interface Card BondingNetwork interface card (NIC) bonding provides additional throughput and/or failover functionality in the event a link islost. The DR4100 supports two bonding modes: dynamic link aggregation and adaptive load balancing (802.3ad andALB). Each of these modes has their own advantages and disadvantages that should be considered before choosing amode.Dynamic link aggregation (Mode 4 or 802.3ad) creates aggregation groups that utilize the same speed and duplex (i.e.10GB and 10GB full-duplex links). Mode 4 (See Figure 1) is highly beneficial in increasing speed and bandwidthcapability for multiple data streams, but will not increase the speed or bandwidth capability of a single data stream.Slave selection for outgoing traffic is executed according to a simple XOR policy. When utilizing mode 4 it is importantto note that the maximum bandwidth available is not always equal to the sum of each link in the bond. Also, alwaysensure that the switch(s) being used support 802.3ad Dynamic link.Figure 1 Dynamic link aggregationAdaptive load balancing (Mode 6 or ALB), the default load balancing mode, is transmit load balancing with the additionof receive load balancing (See figure 2). The receive load balancing uses address resolution protocol (ARP) to interceptpackets and reassign destination MAC addresses. This means that traffic is distributed across slave NICs according tocurrent load. In this mode, it is not possible to mix interfaces of different speeds. (i.e. 10GB and 1GB links) and nospecialized switch support is required. When utilizing mode 6, the total available bandwidth of the bond is equal to thebandwidth of a single physical connection.