Dell Force10 S4820T S4820T Configuration Guide - Page 361

15 Equal Cost Multi-Path (ECMP) Equal Cost Multi-Path (ECMP) is supported on platforms: e c s S4820T ECMP for Flow-based Affinity ECMP for Flow-based Affinity is available on platforms: e S4820T The hashing algorithm on E-Series TeraScale and E-Series ExaScale are different. Hashing on ExaScale is based on CRC, checksum, or XOR, and the algorithm on TeraScale is based on checksum only. If flow-based affinity is to be maintained by an ExaScale and TeraScale chassis, they must both use the same hashing algorithm and seed value, and ECMP must deterministically choose a next hop. Note: IPv6 /128 routes having multiple paths do not form ECMPs. The /128 route is treated as a host entry and finds its place in the host table. Note: Using XOR algorithms will result in imbalanced loads across an ECMP/LAG when the number of members in said ECMP/LAG is a multiple of 4. • Configurable Hash Algorithm • Configurable Hash Algorithm Seed • Deterministic ECMP Next Hop • Link Bundle Monitoring Configurable Hash Algorithm TeraScale has one algorithm that is used for LAGs, ECMP, and NH-ECMP, and ExaScale can use three different algorithms for each of these features. To adjust the ExaScale behavior to match TeraScale, use the following command: Task Change the ExaScale hash-algorithm for LAG, ECMP, and NH-ECMP to match TeraScale. Command Syntax Command Mode hash-algorithm ecmp checksum 0 lag checksum 0 nh-ecmp checksum 0 CONFIGURATION Equal Cost Multi-Path (ECMP) | 361