It probably depends on what you want to do with the info....but how about Netview, OpenView, Spectrum, CiscoWorks, etc? If it's just a one time discovery, Cisco themselves (your sales team/engineer) can run a network collector report for you. It can be used to identify hardware and software that is outdated. We use smaller point products like SolarWinds/Orion/What's UP Gold/Netsite Atlas/etc, but those do have limitations on the number of IP's that can be scanned. You can also look at security tools, which also will scan the whole network, anything from LanGuard/Nessus/similar type products? Are you more interested in monitoring, management, inventory, security...?
