Smart Move; Then the OP will be suspended or very least not able to use the network. The school has every right to guard it`s network and like as not the computer is tied to the school, be it paid or not.
Why suspended? Honestly, if that happened, I'd get a lawyer straight away. Suspended just because you don't want your own computer locked down is bang out of order.
Sure, the school has a right to do what it likes with its own network. But the OP has a right to do what he/she likes with his/her own hardware. If the consequence was simply being locked out the network then that would be no sweat to me. A mobile network dongle would suffice just fine. Or no internet connection whilst at school at all. It isn't as if everybody has a laptop. An internet connection isn't a must have when learning.