A hash engine in a network device driver maintains data on the utilization and error rate for each network interface card (“NIC”) within a local computing device. From this data, the hash engine intelligently selects transmit NICs and receive NICs based on various networking parameters provided from a software driver program. Transmit packets sent from the operating system in a local computing device to a remote computing device are intercepted, modified and redirected to transmit NICs selected by the hash engine for transmission to remote computing devices. Similarly, address resolution protocol (“ARP”) response packets sent by the operating system in response to ARP request packets are intercepted, modified and redirected to receive NICs selected by the hash engine for transmission. By selecting receive NICs and transmit NICs in this fashion, the hash engine is able to intelligently load balance transmit and receive traffic in the local computing device, thereby improving overall network performance relative to prior art techniques.