The 8211 functions exactly like any Ethernet port you will find on a desktop computer. If your PXI controller does not have the driver installed, you can find it here:
http://ni.com/support/vxi/vxi_perph.htm#pxi8210
The same thing applies to the serial ports.
Programming the Ethernet and RS232 ports in CVI will be done the same way you would on any other PC. You may find some examples already written here:
http://ni.com/devzone/dev_exchange/ex_search.htm