nmap does it. But if you need a custom solution you can run many ways. I'll give you two of them

If you already know the address of the Cisco devices, just point nmap to them, get its output (e.g., the XML one) and parse it with one of the many perl modules around (e.g.: XML::Twig)

If you don't know the addresses, well, scan the whole network, get an XML output, select the cisco devices and work on them

You could also generate a report directly from the NMAP XML output using, for example, XML::XPathScript.

Good luck!