With such a wide selection of network devices to choose from in the Cisco product line, an organization can carefully determine the ideal combination to meet the needs of the employees and the customers.

When selecting or upgrading a Cisco IOS device, it is important to choose the proper IOS image with the correct feature set and version. IOS refers to the package of routing, switching, security, and other internetworking technologies integrated into a single multitasking operating system. When a new device is shipped, it comes preinstalled with the software image and the corresponding permanent licenses for the customer-specified packages and features.

For routers, beginning with Cisco IOS Software release 15.0, Cisco modified the process to enable new technologies within the IOS feature sets, as shown in the figure.

The chapter title “IOS Images and Licensing” covers more information on managing and maintaining the Cisco IOS licenses.