"I work for a company with a large IT infrastructure. We have lots of applications in our environment. For a number of applications, vendors provide the apps, and provide core support to those app servers. Our vendors are notorious for demanding superuser access to the boxes that support their applications. To protect our enterprise network from attacks allowed in by well-meaning but less-than-perfectly-competent vendors, we have set up a quarantined network for each vendor.
[...] Frequently vendors can't restrict their applications to run on a limited set of ports. Most of the time they stare blankly when we want their application to run as something less than superuser.
Our biggest challenge is keeping track of all of the dependencies and managing what ports need to be allowed to which destinations. Of course, when security is tight our business-types say 'you're breaking my application.'"