Administrator Guide

Table Of Contents
In-Service Software Upgrade
This chapter deals with In-Service Software Upgrade (ISSU) and its dependencies.
Topics:
ISSU Introduction
Fastboot 2.0 (Zero Loss Upgrade)
L2 ISSU
L3 ISSU
CoPP
Mirroring flow control packets
PFC
QoS
Tunnel Configuration
ISSU Introduction
In-service software upgrades (ISSU), also known as warmboot or fastboot 2.0, allow Dell EMC Networking to address software bugs and
add new features to switches and routers without interrupting network availability. An ISSU eliminates the need to reboot the entire
device. Dell EMC Networking offers ISSU on some switches currently. Generally an ISSU requires a network device with redundant control
plane elements, such as supervisor engines or routing engines. This redundancy allows us to update the software image on one engine
while the other maintains network availability. In Dell EMC Networking switches, the current configuration runs on the NPU while the
system reboots the CPU, this procedure is known as warmboot.
Warmboot Limitations
Warmboot will not work if the following items were changed during the current running configuration:
Changes in cam-profile
Changes in cam-acl-vlan
Changes in ip ecmp-group maximum-path
Changes in cam-ipv6-extended-prefix
Enabling / disabling feature aclrange
Enabling feature vrf
Changes in ALP mode
Stack-unit re-numbering
Fastboot 2.0 (Zero Loss Upgrade)
This feature has been designed to ensure that there is no traffic loss during upgrade of a switch to a different image or while doing a
reload via warmboot.
The user will need to configure the boot-type to warmboot under the reload-type configuration mode. All the supported feature
information gets stored in a persistent storage, and when the switch goes in for a reload, all hardware programmed entries in CAM and FIB
will be saved and traffic will be treated seamlessly, during reload. After the reload is complete, the running-config and startup-config will
be compared and if there is a difference, the device will be programmed based on the startup-config.
L2 ISSU
This section deals with L2 ISSU related information.
The following changes are required by ISSU for L2:
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