One of my previous jobs (back when I was actually employed ) was as an administrator for a firewall service that a major US backbone's internet group provided. We installed Sparc machines running Checkpoint Firewall-1 (and a router) at the customer's site that had multiple NICs, one for the Internet connection and others for the customer's networks. One of our customers was a large company that also had frame relay connections to their other offices, but, for some dumb reason well beyond my control, they didn't have one large frame cloud, but had a separate link for each possible connection. As they had a total of five offices and they wanted a separate connection for each of those links (for, again, no good reason), we needed seven total NICs (1 for the Internet, 1 for the office, 1 for their DMZ, and 4 for the other offices). The engineering group had only approved Sun's QuadFastEthernet adapters, plus the built-in NIC, so we had the one built-in, plus 2 QFEs, for a total of 9 NICs. (Actually, they might have been QEs instead of QFEs.) Now, two of the NICs were unused, but I did have to administer five instances of that setup.