Abstract: A method and system for emulating network latency, packet corruption, packet shuffling, packet loss and network congestion is introduced so that network connected multi-computer software systems can be tested and debugged in a cost effective and efficient manner. This network emulator requires no changes to the software being tested and requires only modifications to the MAC to IP mapping tables of the computers running the software to be tested. IT requires no modification to the communication stacks of the computers involved. The changes to these tables cause packets to be redirected to an emulator host computer where they can be delayed, deleted, corrupted or shuffled prior to delivery to their final destination.