Unified Issu Service Restoration Phase Overview; Application Support For Unified Issu - Juniper SERVICE AVAILABILITY - CONFIGURATION GUIDE V 11.1.X Configuration Manual

Unified ISSU Service Restoration Phase Overview

This is the final unified ISSU phase. At this point, all three major components of the
router the SRP modules, the line module control planes, and the line module
forwarding planes have been upgraded and forwarding has resumed through the
chassis. The following actions take place during this phase:
At this point the unified in-service software upgrade is completed, and the router is
restored to normal operation. Any line modules that reloaded during the upgrade
phase and were therefore held down are now rebooted to the original running release.
Related Topics

Application Support for Unified ISSU

When an application supports unified ISSU, you can configure the application on the
router and proceed with the unified in-service software upgrade with no adverse
impact to the upgrade.
Applications that do not support unified ISSU cannot maintain state and configuration
with minimal traffic loss across the upgrade. When you attempt the unified in-service
software upgrade on a router that is configured with an ISSU-challenged application,
the unified in-service software upgrade is halted and cannot proceed unless you
remove the configuration. An application that does not support high availability
cannot support unified ISSU.
Table 14 on page 72 indicates which applications support or do not support a unified
in-service software upgrade, as well as limitations on their behavior.
The CLI is re-enabled. All commands are made available to users.
The SNMP agent is restarted and bulk statistics are collected and available for
review. (The first interval of bulk statistics collection starts when unified ISSU is
still in process. Therefore, the system performs bulk statistics collection after the
first interval.)
New login requests and logout requests are processed. The router begins to
accept externally created events from sources other than the CLI and SNMP.
These events typically come from user connections, RADIUS servers, and SRC
software and SDX software, and include login requests, COA requests, multicast
join requests, and so on.
Logout requests that were cached at the start of the unified in-service software
upgrade are processed.
After the flash memory on the newly active SRP module is updated, stateful SRP
switchover is available to the router.
Unified ISSU Phases Overview on page 63
Chapter 4: Configuring a Unified In-Service Software Upgrade

Unified ISSU Service Restoration Phase Overview

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