Configuring The Flex Hash Mechanism; Lacp Fast Switchover - Dell C9000 Series Networking Configuration Manual

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Configuring the Flex Hash Mechanism

The flex hash functionality enables you to configure a packet search key and matches packets based on the

search key. When a packet matches the search key, two 16-bit hash fields are extracted from the start of the

L4 header and provided as inputs (bins 2 and 3) for RTAG7 hash computation. You must specify the offset of

hash fields from the start of the L4 header, which contains a flow identification field.

You can enable bins 2 and 3 by using the load-balance ingress-port enable command in Global

Configuration mode. To configure the flex hash functionality, you must enable these bins.

CONFIGURATION mode

Dell(conf)# load-balance ingress-port enable

When load balancing RRoCE packets using flex hash is enabled, the show ip flow command is

disabled. Similarly, when the show ip flow command is in use (ingress port-based load balancing is

disabled), the hashing of RRoCE packets is disabled.

Flex hash APIs do not mask out unwanted byte values after extraction of the data from the Layer 4

headers for the offset value.

Use the load-balance flexhash command to specify whether IPv4 or IPv6 packets must be

subjected to the flex hash functionality, a unique protocol number, the offset of hash fields from the

start of the L4 header to be used for hash calculation, and a meaningful description to associate the

protocol number with the name.

CONFIGURATION mode

Dell(conf)# load-balance flexhash ipv4/ipv6 ip-proto <protocol number>

<description string> offset1 <offset1 value> [offset2 <offset2 value>]

To delete the configured flex hash setting, use the no version of the command.

LACP Fast Switchover causes the physical ports to be aggregated faster when configured in a port-channel

on both the nodes that are members of a port-channel.

When LACP 'fast-switchover' is enabled on the system, two optimizations are performed to the LACP

The wait-while timer is not started in the 'waiting' state of the MUX state machine. The port moves

directly to the 'attached' state.

The local system moves to the 'collecting' and 'distributing' states on the port in a single step without

waiting for the partner to set the 'collecting' bit.

Flex Hash and Optimized Boot-Up