Cisco Cisco IOS Software Release 12.4(20)YA

Use this release note with the documents and websites in this release note and the documents listed in 
the following sections:

The following documents are specific to Release 12.4 and apply to Release 12.4(20)YA. 

Hardware installation guides, configuration and command reference guides, and additional documents 
specific to the Cisco Secure Router 500 Series routers are available at:

The Cisco IOS software documentation set consists of the Cisco IOS configuration guides, Cisco IOS 
command references, and several other supporting documents.

Each module in the Cisco IOS documentation set consists of one or more configuration guides and one 
or more corresponding command references. Chapters in a configuration guide describe protocols, 
configuration tasks, and Cisco IOS software functionality, and contain comprehensive configuration 
examples. Chapters in a command reference provide complete command syntax information. Use each 
configuration guide with its corresponding command reference.

available in html or pdf form.

Select your release and click the command references, configuration guides, or any other Cisco IOS 
documentation you need.

See the “

” section in About Cisco IOS Release Notes located at: 

.