A method for software-based emulation of media access control security (MACsec) includes generating, using a software-based emulated MACsec packet generator, a plurality of emulated MACsec packets, each of the emulated MACsec packets including a MACsec header having a packet number field value that remains fixed across the emulated MACsec packets. The method further includes configuring a device under test to accept plural MACsec packets with the same MACsec packet number field value. The method further includes transmitting the emulated MACsec packets to the device under test (DUT). The method further includes determining whether the DUT responds correctly to the emulated MACsec packets given a replay protection configuration of the DUT. The method further includes generating test output based on a result of the determination.