I have a little trouble in understanding this.. Let's imagine the following situation:
200 PCs with physical connections between - wires, switches and hubs. If all of them are put in one big network (with mask 255.255.255.0 for example) it would be very heavy loaded with broadcasts. So let's diverse that big network to a few little networks with 32 IPs in each via setting the mask to 255.255.255.224. Well, actually such a network won't have 32 IPs, it will have 3 IPs that aren't usable: network number (the first IP), network end (the last IP) and network broadcast. So we have 29 usable IPs.
Here is the question. Does this subnetworking diverse only the broadcasts or all requests? If I am in one subnetwork (physical access to anywhere) can I 'talk' (windows shares, web server, ssh, ip routing, etc..) with IPs in other subnets? If I can't do that, should I raise up virutal IP addreses (aliases) from the other subnets on my one NIC and achieve the goal?

I was reading up on this yesterday and found this article which should help you figure out what you need to do.

Thanks, that was more than satisfying