Depends really, MOST networks these days are setup with a DMZ. A Demilitarized Zone (DMZ) is used by a company that wants to host its own Internet services without sacrificing unauthorized access to its private network. The DMZ sits between the Internet and an internal network's line of defense, usually some combination of firewalls and bastion hosts.
Typically, the DMZ contains devices accessible to Internet traffic, such as Web (HTTP ) servers, FTP servers, SMTP (e-mail) servers and DNS servers.

So basically, IF a network has DMZ set up, all you get is the DMZ network. not the whole network. i have set up networks myself and i do recomend putting in a DMZ coz it always works. THE only way u can bypass a DMZ is by accuiring the routing tables.