Dell PowerSwitch S4128F-ON OS10 Enterprise Edition User Guide Release 10.4.3.0 - Page 493

Usage Information Example The path with the highest weight value is preferred in the best-path selection process. The no version of this command resets the value to the default. OS10(conf-router-bgp-neighbor)# weight 4096 Supported Releases 10.3.0E or later Equal cost multi-path ECMP is a routing technique where next-hop packet forwarding to a single destination occurs over multiple best paths. When you enable ECMP, OS10 uses a hash algorithm to determine the next-hop. The hash algorithm makes hashing decisions based on values in various packet fields and internal values. Configure the hash algorithm in CONFIGURATION mode. hash-algorithm ecmp crc NOTE: The S5148F-ON platform supports only the crc hash algorithm. Change hash algorithm OS10(config)# hash-algorithm ecmp crc Load balancing To increase bandwidth, traffic is balanced across member links. RTAG7 is a hash algorithm that load balances traffic within a trunk group in a controlled manner. RTAG7 balances traffic to more effectively use member links as traffic gets more diverse. RTAG7 generates a hash that consists of two parts: • The first part generates from packet headers to identify micro-flows in traffic. By default, all listed parameters are enabled for load balancing except the ingress port. OS10# show load-balance Load-Balancing Configuration For LAG and ECMP: IPV4 Load Balancing : Enabled IPV6 Load Balancing : Enabled MAC Load Balancing : Enabled TCP-UDP Load Balancing : Enabled Ingress Port Load Balancing : Disabled IPV4 FIELDS : source-ip destination-ip protocol vlan-id l4-destination-port l4-source-port IPV6 FIELDS : source-ip destination-ip protocol vlan-id l4-destination-port l4-source-port MAC FIELDS : source-mac destination-mac ethertype vlan-id TCP-UDP FIELDS: l4-destination-port l4-source-port • The second part generates from the static physical configuration such as the ingress and egress port numbers. To generate load balancing based on any parameters, change the hash field using the load-balance command. Resilient hashing To increase bandwidth and for load balancing, traffic distributes across the next hops of an ECMP group or member ports of a port channel. OS10 uses a hash algorithm to determine a hash key. The egress port in a port channel or the next hop in an ECMP group is selected based on the hash key modulo the number of ports in a port channel or next hops in an ECMP group, respectively. When a member link goes down or a new member link is added, the traffic flows remap based on the new hash result. Layer 3 493