Campus environment firewalling

Hi all,

I'm curious to see how campuses perform firewalling and segmentation within their environments. I know campuses can be much different from Enterprise environments in the fact that their may be multiple IT departments which then utilize a central campus networking service.

In addition to border firewalling how do you handle departmental firewalling?

Do you use a centralized model with large central firewalls?
Or do you have firewalls at each building on campus?
What pros and cons do you see with the method you use (e.g. maintaining, cost, etc.)?
What hardware choices do you use?