IOSMap: TCP and UDP Port Scanning on Cisco IOS Platforms

Robert VandenBrink has publish a paper on SANS detailing how to get a complete port scanner up and running via TCL on cisco IOS.

"This paper describes IOSmap, a port scanning tool implemented on Cisco IOS using the native TCL (Tool
Command Language) scripting language on that platform. The business requirement for this tool,
implementation considerations and challenges, and design choices are discussed."

See more here: www.sans.org