Issu Upgrade For Redundant Platforms; Overview Of Issu On The Cisco Asr 1000 Series Routers - Cisco ASR1000-RP1 - ASR 1000 Series Route Processor 1 Router Software Configuration Manual

ISSU Upgrade for Redundant Platforms

ISSU Upgrade for Redundant Platforms
ISSU represent a full or partial software upgrade of a system from one version to another with minimal
outage on the forwarding plane (minimal packet loss) and no outage on the control plane.
This section covers the following topics:
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Overview of ISSU on the Cisco ASR 1000 Series Routers

For the Cisco ASR 1000 Series Routers, ISSU-compatibility depends on the software subpackage being
upgraded and the hardware configuration. Consolidated packages are ISSU-compatible in dual RP
configurations only and have other limitations described later in this document. Some RP and ESP
software subpackages can be upgraded in service even in single RP or ESP hardware configurations via
dual IOS processes running on the RP; others require dual RP or ESP configurations for an ISSU
upgrade. The SPA and SIP software subpackages must be upgraded on a per-SPA or per-SIP basis. See
Table 4-1
be performed.
If you are updating multiple subpackages, you should also realize that the sequence of the upgrade is
important to minimize router downtime for the software upgrade (see the
SubPackages (Prior to Cisco IOS XE Release 2.1.2)" section on page
The specific procedures in this document represent supported and tested installation sequences. The
Cisco IOS XE system software allows other installation sequences for special purposes under the
guidance of Cisco customer support representatives, but the steps in this document should be followed
otherwise. These steps should be followed completely, as the Cisco ASR 1000 Series Routers are
designed to run one version of Cisco IOS XE for all consolidated packages and subpackages on an RP,
and running subpackages from different versions of Cisco IOS XE can cause unexpected router behavior.
When performing ISSU upgrades on the Cisco ASR 1000 Series Routers, it is important to remember
that minimal interruption upgrades can be performed using either the issu command set or the request
platform command set, and that either command set can be used to perform limited interruption
individual consolidated package or subpackage upgrades.
Note ROMmon images are downloaded separately from Cisco IOS XE images and have their own installation
procedures, and are therefore not mentioned as part in this document as part of the ISSU upgrade
procedure.
Table 4-1
be upgraded without losing any network traffic in single and dual RP and ESP configurations using
ISSU.
Cisco ASR 1000 Series Aggregation Services Routers Software Configuration Guide
4-2
Overview of ISSU on the Cisco ASR 1000 Series Routers, page 4-2
Prerequisites for ISSU, page 4-4
Restrictions for ISSU, page 4-5
ISSU Upgrade Procedures, page 4-5
In Service One-Shot Software Upgrade Procedure, page 4-73
ISSU Procedures (Prior to Cisco IOS XE Release 2.1.2), page 4-73
to view an In Service table that addresses the contexts where limited interruption upgrades can
provides a list of the Cisco ASR 1000 Series Routers subpackages and whether or not they can
Chapter 4 Software Upgrade Process
"Using ISSU to Upgrade
4-74).
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