Cisco IOS Reference Guide

Table of Contents
White Paper: Cisco IOS Reference Guide........................................................................................................1
1.0 Introduction....................................................................................................................................1
2.0 Cisco IOS Trains............................................................................................................................1
3.0 Cisco IOS Releases........................................................................................................................1
4.0 Cisco IOS Feature Sets..................................................................................................................1
5.0 Cisco IOS Images..........................................................................................................................1
6.0 Tools and Resources.......................................................................................................................1
7.0 Important Communications about Releases...................................................................................1
Related Resources...................................................................................................................................1
1.0 Introduction.................................................................................................................................................2
1.1 Growth of Cisco IOS.....................................................................................................................2
1.2 Scope of this Document.................................................................................................................2
2.0 Cisco IOS Trains.........................................................................................................................................2
2.1 Types of Trains..............................................................................................................................3
2.2
Mainline and T Train Relationship...............................................................................................3
2.3
Train Lifecycle Milestones...........................................................................................................4
3.0 Cisco IOS Releases....................................................................................................................................5
3.1. Types of Releases.........................................................................................................................5
3.2 Maintenance Releases....................................................................................................................5
3.3 Rebuild Releases............................................................................................................................6
3.4 General Deployment (GD) Releases..............................................................................................6
3.5 Special Releases.............................................................................................................................7
3.6 Interim Builds................................................................................................................................9
4.0 Cisco IOS Feature Sets..............................................................................................................................9
4.1. Cisco IOS Packaging....................................................................................................................9
5.0 Cisco IOS Images.....................................................................................................................................10
5.1 Image Naming..............................................................................................................................10
5.2 Images Running on a Router........................................................................................................10
6.0 Tools and Resources.................................................................................................................................11
6.1 Tools............................................................................................................................................11
6.2 Cisco IOS Roadmap.....................................................................................................................11
7.0 Important Communcations about Releases...............................................................................................11

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2 2.2 3. This document describes the release model—trains.0 Tools and Resources Tools Cisco IOS Roadmap Important Communications about Releases Related Resources • Cisco IOS Roadmap • The ABC's of Cisco IOS Software: Understanding the Essentials Series • Cisco IOS Software Technical Documentation Cisco IOS Reference Guide .0 4.4 3.1 6. implementing.2 Image Naming Images Running on a Router 6. feature sets. releases.3 3. and managing network infrastructures.0 3. designing.1 3.White Paper: Cisco IOS Reference Guide Understanding the Cisco IOS® Software release model is essential for planning.2 7. see Cisco IOS Software Technical Documentation.0 6.1 2.0 2.5 4.1 Cisco IOS Trains Types of Trains Mainline and T Train Relationship Train Lifecycle Milestones Cisco IOS Releases Types of Releases Maintenance Releases Rebuild Releases GD Releases Special Releases Cisco IOS Feature Sets Cisco IOS 12.1 5.1 1. For information about how to install or configure Cisco IOS Software. 1. and images.2 Growth of Cisco IOS Scope of this Document 2.0 Introduction 1.3 Packaging 5.0 Cisco IOS Images 5.3 3.

Cisco IOS Software diversified from one train of releases to multiple trains supporting different feature sets for different customer needs. 1.1 Growth of Cisco IOS The Internet was a driving force in Cisco’s growth.0 Introduction Cisco IOS Software is network system software that tightly integrates a broad range of Internet and enterprise network hardware. Cisco IOS Reference Guide . 1. wireless. storage networking. such as Feature Navigator and Upgrade Planner • The Cisco IOS roadmap 2. It enables network services and Internet applications. applications. minimizing costs. serving as an end−to−end solution for global networking. such as voice and video over IP networks.• Software Center: Cisco IOS Software • Cisco IOS Upgrade Planner • Cisco Feature Navigator • What's New for Cisco IOS Software 1. Customers can leverage their investment in Cisco hardware and software solutions for years. Cisco IOS Software is the unifying thread that connects otherwise disparate networks to build a scalable network infrastructure. To perform these critical tasks. network administrators must understand the following topics: • The evolution of Cisco trains and releases • The names of trains and releases • The types of trains and releases To obtain new Cisco IOS images. so did Cisco’s growth. with the addition of thousands of new features.2 Scope of this Document This document is intended for network administrators who upgrade and maintain a network. hundreds of new applications. and ensuring investment protection. Cisco IOS Software supports new areas of networking technology. optical. As the router market exploded. Cisco IOS Software evolved over time and met the challenge of rapid changes in the business and network environment in the last decade. In recent years. Today. network administrators must understand the following topics: • Feature sets and images • Cisco IOS tools. and a wide array of platforms. Cisco routers ran Cisco IOS Software. and network services to support e−commerce conducted over multi−service (Data/Voice/Video) applications.0 Cisco IOS Trains A Cisco IOS train is a vehicle for delivering releases that evolve from a common code base. Cisco IOS Software supports an unparalleled array of features. maximizing ROI. and an array of hardware that ensures its longevity. From the beginning.

supports advanced QoS.1 Types of Trains Today.2 Mainline and T Train Relationship Early in Ciscos history.1 T Train and Mainline Evolution Mainline trains. voice.3 additional features. such as 12. and fixes defects.1E B Supports broadband features and fixes defects. are built from previous generation T trains. and firewall. the need for at least two trains for releasing Cisco IOS Software emerged: • A train for bug fixesmainline • A train for bug fixes and new featuresT train With two trains.2.2T (see Figure 1). which supports high−end backbone routing. such as 12. 12.2 mainline. Figure 1: Evolution of T and Mainline Trains Cisco IOS Reference Guide .0S. and 12.2B. 12. 12. such as 12.1T. Inherits features from the parent T train.0S.3B 2. T Introduces new features and fixes defects. and fixes defects.3T S Consolidates 12. security. 12.2. 12. 12.2. Cisco IOS releases are delivered on the following types of trains: Table 1: Types of Trains Train Description Examples mainline Consolidates releases and fixes defects.2S E Targets enterprise core and SP edge.2. 12. 12. and does not add 12. Mainline trains. are parents of other trains. 2.2. such as 12.1E. Cisco could introduce new features in a Cisco IOS release from one train without affecting the code base of the other train.

maintaining. The following acronyms are associated with lifecycle milestones: • FCSFirst Customer Shipment • EoSEnd of Sale • EoEEnd of Engineering • EoLEnd of Life The following table briefly describes the train lifecycle milestones.3 Train Lifecycle Milestones At some point in the life of a train. Cisco informs customers that a train has reached one of these milestones by issuing product bulletins and other communications.com FCS Yes Yes* Yes Yes EoS No Yes Yes Yes EoE No No Yes Yes EoL No No No No * FCS corresponds to the first maintenance release on the train. and supporting it. Table 2: Milestones in the Life of a Train Milestone Available through Sales Channels Bug Fixes TAC Support Download from Cisco.2 Bug Synchronizing and Feature Integration Bug fixes to maintenance releases on a mainline train are synchronized with subsequent maintenance releases on the child T train (see Figure 2). Each new release receives regular maintenance during the early part of the life cycle. New features are integrated into the T train onlythe mainline train receives bug fixes only.2. Figure 2: Bug Synchronizing and Feature Integration 2. Cisco stops selling. Cisco IOS Reference Guide .2.

1 Maintenance Release Naming A maintenance release name. so customers can determine which T and S train release gets bug fixes from a particular mainline release. depending on the train. T.2. such as 12. or both.0 Cisco IOS Releases A release is a snapshot in time of the code base of a train.2.2(3)T.3. Figure 4: Maintenance Release Number Sharing Between Mainline. Types of Releases • Maintenance releases • Rebuild releases • General Deployment (GD) releases • Special releases 3. Figure 3: Example of Maintenance Release Name 3.1. Maintenance releases typically occur every eight to thirteen weeks.2 Cisco IOS Maintenance Release Revision Number Sharing Bug fixes are synchronized from the mainline to the T train (see Figure 2). has a number enclosed in parentheses (see Figure 3). T. and S trains (see Figure 4). With the release of the 12. Cisco started sharing a sequence of numbers among maintenance releases on the mainline.2 Maintenance Releases A maintenance release is a scheduled revision of Cisco IOS Software that introduces new features or bug fixes. and S Trains Cisco IOS Reference Guide . 3. 3.2 mainline train.

3. such as 12. Cisco IOS releases achieve GD status after meeting strict standards. Figure 5: Example of a Rebuild Release Name—T Train A lowercase alphabetic suffix in a release name. or E train (see Figure 5). Figure 6: Example of a Rebuild Release Name—Mainline Train 3.1 Rebuild Release Naming A numeric suffix in a release name. T. indicates a rebuild of a maintenance release on a mainline train (see Figure 6). 3.3 Rebuild Releases Circumstances and business demands may require that a number of images from a Cisco IOS train be rebuilt and posted prior to the next planned maintenance release.3. indicates a rebuild of a maintenance release on a B. S.4 General Deployment (GD) Releases A Cisco IOS Software release reaches GD certification when its quality has been demonstrated by extensive deployment in diverse networks over extended periods of time. 3.2(8)T1. defect resolution commits only ♦ No open Critical Account Program (CAP) issues ♦ Defect density measurements ♦ Software Reliability Engineering (SRE) projected defects ♦ Minimal code changes No serious defects in previous maintenance releases • Customer Success ♦ Extensive customer exposure ♦ High level of customer satisfaction Cisco IOS Reference Guide . Rebuilds are a Cisco IOS vehicle that delivers fixes on an accelerated schedule.1 General Deployment (GD) Release Criteria A GD release must meet the following criteria: • Improving Trend in Defect Backlog ♦ Customer Advocacy (CA) evaluation of known defects ♦ No new features or platforms.4.2(1a). such as 12.

or Z. Special release names do not conform to a strict naming convention.5 Special Releases A special release is a branch from a train code base that is introduced to quickly meet market demands for new features or additional platform support. one time release Z A Aggregation/Access Server/Dial D xDSL H SDH/SONET J Aironet Wireless Networking M Mobile Wireless W 3. Figure 7: Release Name Example 1 Cisco IOS Reference Guide . modification of the code. including bug fixes. it enters a restricted maintenance phase. is strictly limited and controlled by a program manager to prevent bugs from being introduced into the release. 3. A−Z.2 General Deployment (GD) Lifecycle After a release attains GD status. The second letter can be a sequential revision identifier. When this type of naming is used. Figure 7 shows an example of a special release name. the first letter of the double letter identifier can represent the one−time release X. While in this phase.4.• Cisco Deployment ♦ Comprehensive system test and deployment in Cisco's internal network • Documentation ♦ Release Notes Enclosures (RNEs) complete 3. The early field adoption of new features and platforms that Cisco introduces in special releases benefits customers who need to run new network equipment or services. Consequently.1 ATM/LAN Switching/Layer 3 Switching Naming of Special Releases The names of special releases have double letter identifiers after the train and maintenance release numbers. The following table lists technology identifiers used in the names of special releases. 12. Table 3: Special Release Technology Identifiers Identifier Target Technology or Platform X Y Varies. every subsequent revision of the release is also GD.5. when a release is declared GD.2(2)XB. Y.

The second letter represents the one−time release X. Figure 8: Release Name Example 2 Figure 9 shows an example of another type of special release name. Figure 10: Integration of Special Release Features into Parent Cisco IOS Reference Guide . a special release is integrated back into the parent train (see Figure 10). The first letter of the double letter identifier indicates the technology the release delivers (see Table 3).Figure 8 shows an example of another type of special release name. 3.5.2(2)EX. the first letter of the double letter identifier designates the parent of the special release. or Z.2(2)JA. 12. Y. The second letter is a sequential revision identifier A−Z. 12.2 Feature Migration of Special Releases At some point in its lifecycle. Figure 9: Release Name Example 3 Maintenance or rebuild identifiers (not shown in Figures 7−9) follow the double letter special release designator. When this type of naming is used.

3.5.3 for the Cisco 1700.3 Packaging Feature Sets Cisco IOS Reference Guide . and 3700 series routers.0 Cisco IOS Feature Sets A feature set is a bundle of the features available for a release. Other hardware platforms will be introduced with Release 12.2(3. 2600. Figure 12: Cisco IOS 12. 3. Customers can use multiple feature sets of a release.3 Packaging is initially available for Release 12.3.1) has a train number plus a maintenance release number and decimal number in parentheses (see Figure 11).1.3 Packaging introduces eight new feature sets (see Figure 12).1 Interim Build Naming An interim build name.3 Packaging simplifies the feature set selection process by consolidating the number of packages and using consistent package names across all platforms. Figure 11: Example of an Interim Build Name 4.6. Cisco IOS 12.3T. such as 12. 4. Cisco IOS 12. Customers who have an interim build installed on their network should contact TAC for assistance in replacing the interim build. Cisco IOS Packaging Cisco IOS 12. Along with Cisco IOS legacy images.3 Lifecycle of Special Releases Cisco’s end of life (EoL) policy is not applicable to special releases.6 Interim Builds An interim build is software from an internal Cisco engineering build process that the Cisco Technical Assistance Center (TAC) gives customers to use on a temporary basis to address a specific issue.

feature set. format. Multiple images exist for a release. Figure 13: Example of an Image Name Refer to the Cisco IOS Software Image Naming Convention for information about identifying the platform or board for which the binary software is built. 5. 5. and the area of memory used by the image at run time.3(2)T release with the Enterprise Base feature set for the Cisco 3725 platform. The following example shows the image name of a 12. Cisco IOS Reference Guide . and other information about the image file.5. the package feature content of the image.1 Image Naming The software image name represents the platform.0 Cisco IOS Images A Cisco IOS image is a binary executable file of a feature set for a specific platform. representing supported platform and feature set combinations.2 Images Running on a Router The show version command displays the name of the Cisco IOS image that is running on a device.

Often. Software Advisor Compares IOS releases. customers are strongly urged to migrate from the affected image to the replacement image. • Deferral AdvisoryCisco issues a deferral advisory to announce the removal of a Cisco IOS image from Cisco's offerings and to introduce a replacement image. Bug Toolkit Searches for known bugs based on software version. do not affect most customers. A deferral advisory is most often issued to correct a defect. software advisories describe problems with Cisco IOS Software that are platform specific or occur under unusual circumstances. release. no action is required by the customer.0 Tools and Resources The Cisco IOS toolbox is a table that briefly describes and lists links to important Cisco IOS tools and documentation. At the time that the deferral of a Cisco IOS image is advised. and finds out which software release supports a given hardware device. 6. Cisco IOS Upgrade Planner Finds releases by platform. and images.2 Cisco IOS Roadmap The Cisco IOS roadmap consists of graphical links to detailed information about specific Cisco IOS releases and trains. and compares releases. Important Notices and Privacy Statement. or to make recommendations to mitigate general problems affecting network stability. Often.0 Important Communcations about Releases Cisco issues many software advisories to customers for informational purposes only.1 Tools The following table briefly describes some of the most useful tools in the Cisco IOS toolbox. platforms. All contents are Copyright © 1992−−2003 Cisco Systems Inc. The roadmap shows the lineage of releases. Customers can use the tools to get information about releases. feature set.6. Cisco IOS Reference Guide . 6. matches IOS and CatOS features to releases. Feature Navigator Finds releases that support a set of software features and platforms. Table 4: Key Cisco IOS Tools Tool Description Software Selector Finds required features for a given technology. and feature set. and keywords. 7. Critical communications about releases from Cisco that do require action include: • Security AdvisoryProduct Security Incident Response Team (PSIRT) issues a security advisory to alert customers to security issues that directly impact Cisco products and to help customers repair the Cisco product. • Security NoticesCisco issues Security Notices about issues that require a response to information posted to a public forum. and downloads images of Cisco IOS Software. All rights reserved. and therefore. feature sets.