Whats with all the Cat5 plugs?

I was just curious why a server would have 4 RJ-45 ports along with 2 NIC cards? I noticed this on a server at work that had Cat5 cables in all of them except one of the NIC cards.

If you guys want pictures let me know. But I was just wondering what the purpose of all them was.

ZiPPy

It's must either be more than one NIC on the same PCI interface (useful to save space on the motherboard) or a PCI TAP device, used for sending a copy of the NIC's traffic somewhere else for auditing purposes.

i agree with nske, i have seen a 4 interface ethernet card

We have several of these 4-port Ethernet cards in firewalls. The card can either act as four Ethernet NICs or as a 4-port Ethernet switch internal to the server, depending on how you install it.
Another possibility, more likely on high-end kit, is that they provide extra console (serial) and administrative ports that also use RJ45s. I've seen this on some Solaris boxes but may be on other servers too

You can also use interface bonding in Linux/*BSD to take advantage of the total bandwidth of multiple interfaces, for one link (something similar to Etherchannel technology in Cisco devices).

I think you can do that in Windows Server too (not sure though, correct me if I'm wrong).