Dell C1048P Port Extender Networking Command-Line Reference Guide for the C900 - Page 845

The following is a list of the Dell Networking OS version history for this command. Version 9.9(0.0) 9.2(1.0) 8.3.19.0 8.3.11.1 8.3.7.0 8.3.1.0 Description Introduced on the C9010. Introduced on the Z9500. Introduced on the S4820T. Introduced on the Z9000. Introduced on the S4810. Introduced on the E-Series. Usage Information Deterministic ECMP sorts ECMPs in order even though RTM provides them in a random order. However, the hash algorithm uses as a seed the lower 12 bits of the chassis MAC, which yields a different hash result for every chassis. This behavior means that for a given flow, even though the prefixes are sorted, two unrelated chassis select different hops. The system provides a CLI-based solution for modifying the hash seed to ensure that on each configured system, the ECMP selection is same. When configured, the same seed is set for ECMP, LAG, and NH, and is used for incoming traffic only. NOTE: While the seed is stored separately on each port-pipe, the same seed is used across all CAMs. You cannot separate LAG and ECMP but you can use different algorithms across the chassis with the same seed. If LAG member ports span multiple port-pipes and line cards, set the seed to the same value on each port-pipe to achieve deterministic behavior. If the hash algorithm configuration is removed, the hash seed does not go to the original factory default setting. ip ecmp-group Enable and specify the maximum number of ecmp that the L3 CAM hold for a route, By default, when maximum paths are not configured, the CAM can hold a maximum of 16 ecmp per route. C9000 Series Syntax ip ecmp-group {maximum-paths | {number} {path-fallback} To negate a command, use the no ip ecmp-group maximum-paths {number} command. Equal Cost Multi-Path (ECMP) 845