Table Of Contents
Release Notes for Cisco IOS Release 12.3
March 18, 2008
Cisco IOS Release 12.3(26)
Note See the "Important Notes" section on page 232 for important information for Cisco IOS Release 12.3.
These release notes support Cisco IOS Release 12.3. They are updated to describe new hardware support, software platform deferrals, and related documents.
Cisco IOS Release 12.3(22) and all subsequent 12.3 releases are deemed "Generally Deployable." We believe that Release 12.3 is suitable for deployment anywhere in the network where the features and functionality of the release are required.
For a list of the software caveats that apply to Cisco IOS Release 12.3, see the Caveats for Cisco IOS Release 12.3 document, which accompanies these release notes. The caveats document is updated for every maintenance release and is located on Cisco.com.
We recommend that you view the field notices for this release to see if your software or hardware platforms are affected. If you have an account on Cisco.com, you can find field notices at http://www.cisco.com/public/support/tac/fn_index.html. If you do not have a Cisco.com login account, you can find field notices at http://www.cisco.com/public/support/tac/fn_index.html.
These release notes contain the following sections:
Cross-Platform System Requirements
This section describes the system requirements for Cisco IOS Release 12.3 and includes the following sections:
Supported Hardware Platforms
Cisco IOS Release 12.3 supports the following Cisco hardware platforms:
•SOHO 70 series routers
•Cisco Catalyst 4224 access gateway switches
•Cisco CVA120 series
•Cisco Catalyst 4500 access gateway modules
•Cisco Voice Gateway 200
•Cisco AS5300 universal access servers
•Cisco 800 series routers
•Cisco AS5350 universal gateways
•Cisco uBR900 series
•Cisco AS5400 universal gateways
•Cisco 1400 series
•Cisco AS5800 universal access servers
•Cisco 1600/1600R series
•Cisco AS5850 universal gateways
•Cisco 1700 series
•Cisco 6400 family1
•Cisco IAD2420 series
•Cisco 7000 family
•Cisco 2500 series
•Cisco 2600 series
•Cisco IGX 8400 series URM
•Cisco 3600 series
•Cisco MGX 8850 route processor modules3
•Cisco 3700 series
•Cisco signaling link terminals
•Cisco MC3810 multiservice access concentrators4
1 The Cisco 6400 is not supported in Cisco IOS Release 12.3(13) and later releases.
2 The Cisco ICS7750 is not supported in Cisco IOS Release 12.3(3) and later releases.
3 The Cisco MGX 8850 RPM is supported in Cisco IOS Release 12.3(3).
4 The Cisco MC3810 is not supported in Cisco IOS Release 12.3(19) and later releases.
For detailed descriptions of the new hardware features, see the "New and Changed Information" section on page 107.
Determining Your Software Version
To determine the version of Cisco IOS software that is currently running on your Cisco network device, log in to the device and enter the show version EXEC command:Router> show versionCisco Internetwork Operating System SoftwareIOS (tm) 12.3 Software (C2600-I-MZ), Version 12.3(1), RELEASE SOFTWARE . . .
Upgrading to a New Release
For information about selecting a new Cisco IOS software release, please refer to How to Choose a Cisco IOS Software Release at:
For information about upgrading to a new software release, refer to the appropriate platform-specific documents:
•Cisco 1400 Series Routers
•Cisco 1600 Series Routers
•Cisco 1700 Series Routers
•Cisco IAD2420 Integrated Access Device
•Cisco 2500 Series Routers
•Cisco 2600 Series Multiservice Platforms
•Cisco 3600 Series Multiservice Platforms
•Cisco 3700 Series Multiservice Access Routers
•Cisco MC3810 Multiservice Access Concentrators
•Catalyst 4224 Access Gateway Switch
•Cisco Catalyst 4500 Series Switches
•Cisco AS5300 Series Universal Gateways
•Cisco AS5400 Series Universal Gateways
•Cisco AS5800 Series Universal Gateways
•Cisco 6400 Series Broadband Aggregators
•Cisco 7200 Series, 7300 Series, 7400 Series, and 7500 Series Routers
•Cisco ICS 7700 Series Integrated Communication Systems
To choose a new Cisco IOS software release by comparing feature support or memory requirements, use Cisco Feature Navigator. Cisco Feature Navigator is a web-based tool that enables you to determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image. You can search by feature or by feature set (software image). Under the release section, you can compare Cisco IOS software releases side by side to display both the features unique to each software release and the features that the releases have in common.
Cisco Feature Navigator is updated regularly when major Cisco IOS software releases and technology releases occur. For the most current information, go to the Cisco Feature Navigator home page at the following URL:
To choose a new Cisco IOS software release based on information about defects that affect that software, use Bug Toolkit at: