Reference Guide

Equal Cost Multi-Path (ECMP) | 353

Equal Cost Multi-Path (ECMP)

Equal Cost Multi-Path (ECMP) is supported on the S5000 switch.

This chapter contains the following sections:

• ECMP for Flow-based Affinity

• Managing ECMP Group Paths

ECMP for Flow-based Affinity

ECMP for Flow-based Affinity is available on the S5000 switch.

• Deterministic ECMP Next Hop

• Configuring Hash Algorithm Seed

• Link Bundle Monitoring

Deterministic ECMP Next Hop

Deterministic ECMP Next Hop arranges all ECMPs in order before writing them into the CAM. For

example, suppose the RTM learns 8 ECMPs in the order that the protocols and interfaces came up. In this

case, the FIB and CAM sort them so that the ECMPs are always arranged.This implementation ensures that

every chassis having the same prefixes orders the ECMPs the same.

With 8 or less ECMPs, the ordering is lexicographic and deterministic. With more than 8 ECMPs, ordering

is deterministic, but it is not in lexicographic order.

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.

Task Command Syntax Command Mode

Enable IPv4 Deterministic ECMP Next

Hop.

ip ecmp-deterministic

CONFIGURATION