General Unified Issu Considerations For All Platforms - Juniper EX9200 Features Manual

High Availability Feature Guide for EX9200 Switches

General Unified ISSU Considerations for All Platforms

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Unified ISSU has the following caveats:
We recommend that you not use unified ISSU to upgrade from an earlier Junos OS
release to Junos OS Release 14.2.R1 or 15.1.R1. For more information about Junos OS
Release 14.2 see
http://www.juniper.net/techpubs/en_US/junos14.2/information-products/topic-collections/release-
notes/14.2/junos-release-notes-14.2r1.pdf
15.1, see
http://www.juniper.net/techpubs/en_US/junos15.1/information-products/topic-collections/release-
notes/15.1/junos-release-notes-15.1.pdf
The master Routing Engine and backup Routing Engine must be running the same
software version before you can perform a unified ISSU.
The unified ISSU process is aborted and a message is displayed if the Junos OS version
specified for installation is a version earlier than the one currently running on the device.
The unified ISSU process is aborted if the specified upgrade has conflicts with the
current configuration, components supported, and so forth.
You cannot take PICs offline or bring them online during a unified ISSU.
User-initiated GRES is blocked when the device is undergoing a unified ISSU.
Unified ISSU does not support extension application packages developed with the
Junos SDK.
To downgrade from a unified ISSU-capable release to a previous software release
(unified ISSU-capable or not), use the
command. Unlike an upgrade using the unified ISSU process, a downgrade using the
request system software add package-name
and loss of data. For more information about the use of the
add package-name command, see the Installation and Upgrade Guide.
Unicast reverse-path-forwarding (RPF)-related statistics are not saved across a unified
ISSU, and the unicast RPF counters are reset to zero during a unified ISSU.
BGP session uptime and downtime statistics are not synchronized between the master
and backup Routing Engines during a unified ISSU. The backup Routing Engine maintains
its own session uptime based on the time when the backup first becomes aware of
the established sessions. For example, if the backup Routing Engine is rebooted (or if
you run restart routing on the backup Routing Engine), the backup Routing Engine
uptime is a short duration, because the backup has just learned about the established
sessions. If the backup is operating when the BGP sessions first come up on the master,
the uptime on the master and the uptime on the backup are almost the same duration.
After a Routing Engine switchover, the new master continues from the time left on the
backup Routing Engine.
If proxy ARP is enabled on your device, you must delete the
statement from the
[edit interfaces interface-name unit 0 family inet]
before the unified ISSU process begins and include it after the unified ISSU process is
complete. Note that the
. For more information about Junos OS Release
.
request system software add package-name
command can cause network disruptions
statement is not included by default.
unconditional-src-learn
request system software
unconditional-src-learn
hierarchy level
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