Deployment Guide

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
DellEMC(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
DellEMC(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 has no effect. If you configure the optimized booting-time capability and perform a reload of the
system, the LACP application sends PDUs across all the active LACP links immediately.
INTERFACE (conf-if-po-number) mode
DellEMC(conf-if-po-number)#lacp fast-switchover
Optimizing the Boot Time
You can reduce the booting time of a switch by using the fast boot feature. With the reduced time that is taken to reboot
the switch, upon a manually-initiated reload or an expected restart of the device, there is minimal disruption in the traffic that
is managed by the switch. Traffic outage is lowered considerably (reduced to approximately 25 seconds in certain network
deployments) when you enable this optimization method while booting the device. By reducing the duration of traffic loss, the
subscriber sessions are processed and preserved in an effective and seamless way.
You can configure this capability on the switch that is deployed as a top-of-rack (ToR) switch. The ToR switch is the single
point of connection to the network for servers in that rack. This functionality of minimized reload time is supported in a network
deployment in which the servers are connected through a ToR, leaf and spine unit or configuration setup. An exterior border
gateway protocol (EBGP) session exists between the ToR and leaf switch units, and between the leaf and spine units or nodes.
Booting Process When Optimized Boot Time Mechanism is Enabled
When device running Dell EMC Networking OS earlier than Release 9.3(0.0) is reloaded, the CPU and other components on
the board are reset at the same time. Therefore, the control plane and the forwarding plane are impacted immediately. After
the system boots up and re-initializes, the interfaces come up, control plane protocols are reestablished, and the network
topology information (such as routes, adjacency settings) is learned and installed before the traffic resumes. In a typical network
scenario, a traffic disconnection of 150 seconds or more usually occurs. When you employ the optimized booting functionality,
the traffic outage duration is reduced drastically.
Guidelines for Configuring Optimized Booting Mechanism
Keep the following points and limitations in mind when you configure the fast boot capability:
● Fast boot is supported only when you perform an expected, stipulated reload by using the reload-type normal-
reload command in Global Configuration mode or by using the reset command in uBoot mode on a switch that is
running Dell EMC Networking OS Release 9.3(0.0) or later, or when you perform a planned upgrade (and not an abrupt or
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Flex Hash and Optimized Boot-Up