It’s hit and miss. You’re not supposed to be able to but for some you can. Also depends on planetary alignments.
The LANs were seperated by closet due to viruses that were able to spread over network shares. It didn’t help against the massive rinbot outbreak but several others were isolated so they decided to keep the policy.
I have to admit it was quite funny sitting in one of the Belk labs in a lecture and watching as the computers caught rinbot one by one. You don’t really respect the power of these types of malware until you’re sitting in a room full of IRC drones.