If you configure two networks using different IP ranges and let them share cables, hubs and switches - can they communicate and would that be a security risk?
Say, one configured on 192.168.0.*, and the other on 10.0.0.*. Could viruses or other attacks (eg. Blaster), spread from one network to the other?
And if you have one computer with two NICs, each configured for each range and a software firewall only allowing for communication on port 80. Does this make the net vulnerable?
The motivation for this is to use the same cables for a production network and an administration network, saving some money and not lowering security. The networks must be able to communicate to provide web production reports for the administration.