Dell Force10 S25N-S50N FTOS Configuration Guide FTOS 8.4.2.7 E-Series TeraScal - Page 436

www.dell.com | support.dell.com Load balancing through port channels FTOS uses hash algorithms for distributing traffic evenly over channel members in a port channel (LAG). The hash algorithm distributes traffic among ECMP paths and LAG members. The distribution is based on a flow, except for packet-based hashing. A flow is identified by the hash and is assigned to one link. In packet-based hashing, a single flow can be distributed on the LAG and uses one link. Packet based hashing is used to load balance traffic across a port-channel based on the IP Identifier field within the packet. Load balancing uses source and destination packet information to get the greatest advantage of resources by distributing traffic over multiple paths when transferring data to a destination. FTOS allows you to modify the hashing algorithms used for flows and for fragments. The load-balance and hash-algorithm commands are available for modifying the distribution algorithms. Their syntax and implementation are somewhat different between the E-Series and the C-Series and S-Series. Note: Hash-based load-balancing on MPLS does not work when packet-based hashing (load-balance ip-selection packet-based) is enabled. E-Series load-balancing On the E-Series, the default load-balance criteria are a 5-tuple, as follows: • IP source address • IP destination address • Protocol type • TCP/UDP source port • TCP/UDP destination port Balancing may be applied to IPv4, switched IPv6, and non-IP traffic. For these traffic types, the IP-header-based hash and MAC-based hash may be applied to packets by using the following methods. Table 20-5. Hash Methods as Applied to Port Channel Types Hash (Header Based) 5-tuple 3-tuple Packet-based MAC source address (SA) and destination address (DA) Layer 2 Port Channel X X X X Layer 3 Port Channel X X X 436 | Interfaces