You can install them on same server, but It is not advised to install any Cisco Secure software on the CiscoWorks server. The
problem is that both products use the same system resources and both use a lot of network bandwidth. CiscoWorks has a daemon that periodically polls your devices. CiscoSecure is a real-time application that needs to reply to requests from your devices quickly. During the CiscoWorks' polling time, CiscoSecure may have problems responding quickly enough to user requests and they may be denied access to your network. Also, CiscoSecure may interfere with CiscoWorks' management of your devices.
