Using only 2 pairs of Ethernet
The resistors are there to terminate the unused pairs absorbing any signals they may have picked up. 

They're usually added to improve EMI, and prevent signals that have crosstalked from the other pairs bouncing back and forth in the un-useds pairs potentially degrading the signals in the pairs that you are using.

You can happily live without them, especially if your cable run (including any structured wiring you use) is short.