Tuning a network interface card (NIC) for optimum throughput and latency is a complex process with many factors to consider. These factors include capabilities of the network interface, driver features and options, the system hardware that Red Hat Enterprise Linux is installed on, CPU-to-memory architecture, amount of CPU cores, the version of the Red Hat Enterprise Linux kernel which implies the driver version, not to mention the workload the network interface has to handle, and which factors (speed or latency) are most important to that workload. There is no generic configuration that can be broadly applied to every system, as the above factors are always different. The aim of this document is not to provide specific tuning information, but to introduce the reader to the process of packet reception within the Linux kernel, then to demonstrate available tuning methods which can be applied to a given system.