My query is :
If I want to connect a server to a switch (all 100mbps ports) in such a way that the switch's two ports (100mbps each) should act as one (aggegation) and at other end connected to server's two NIC cards. Do i require a special NIC for this to be done, like one of my senior suggested they should be 802.1Q supported. I want to know why do we need Dot1Q supported nic's for such thing to do. I'm not sure if he got confused between dot1q and PAgP.
Bandwidth Aggregation requires port-bundling (ether-channeling to be exact). Trunking is the ability to have more than one Vlan on a single link.
You don't need a special NIC for port-bundling, however, you need the software on the NIC to support such feature. On the server side, you may be looking at LACP.
You often see terms such as "teaming" when configuring port-bundling on the server side.
Intel has some nice write-ups.