• NetworkInfo::Discovery
• CISCO

Net::SNMP is probably a good place to start. If you search CPAN for 'Cisco' you will find lots of stuff.

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!

In a nutshell, you'll either automate a series of Telnet sessions or a series of SNMP queries.   For the former, I'd strongly recommend using the Net::Telnet::Cisco CPAN module, and for the latter probably the Net::Snmp CPAN module.   The telnet approach might maybe be slightly easier, but SNMP efforts could well be less fragile and more secure.

More specifically, the code section on my homenode lists several Cisco-ey scripts, a few of which might give you a good head start.

• (code) Poor Man's TACACS - automate CatOS and IOS password resets with Net::Telnet::Cisco and Net::SNMP
• (code) Net::SNMP, Bandwidth, GnuPlot, PNG, PostScript, Excel
• (code) Resolve list of DNS names
• (code) Net::SNMP, table-ish interface stats
• (code) Cisco errdisable (no password timeout if Win32)
• (code) Cisco sho ver
• (code) Cisco Neighbors
• (code) mind your snmPs & Qs
• (code) MAC n' IP cheese