Ethernet Port Switching

Hey,

First a little background...

I have a Desktop PC that is connected to Dell Switch of 100 ethernet ports. I have a different ethernet source coming out of the first 20 ports.

What im trying to do is isolate one of the sources coming out of the switch and disable the other 19. I then want to manually run a few tests and then when I decide, I want to switch to another source. (if at 2 goto 3 if at 14 goto 15) How would i began to write a code that would do this?

Thanks

Brandon T