Users Guide

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.
1 In Dell Networking OS Release 9.3(0.0), 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.
2 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.
Configuring Fast Boot and LACP Fast
Switchover
Configure the optimized booting time functionality by performing the following steps.
1 Enable the system to restart with optimized booting-time functionality enabled.
CONFIGURATION mode
Dell(conf)#reload-type fastboot
2 Configure fast boot on a port-channel on both the nodes that are members of a port-channel in order
to enable the physical ports to be aggregated faster. You can configure the optimal switchover
functionality for LACP even if you do not enable the fast boot mode on the system. This command
applies to dynamic port-channel interfaces only. When applied on a static port-channel, this command
Flex Hash and Optimized Boot-Up 355