In this paper, the performance of IEEE 802.11ac wireless LAN using IPv4, IPv6, TCP, UDP, peer-peer, and client-server networks is investigated while implementing WPA2 security. The latest operating systems are used in the study, Windows 10 for workstations and Server 2016 for the server. Packet sizes used range from 128 to 1408 Bytes. Parameters measured were bandwidth, Round Trip Time (RTT), and CPU utilisation. For TCP, client-server WLAN with IPv4 has the highest throughput for all packets, having 105 Mbps for packet size of 128 Bytes and 620 Mbps for packet size of 1408 Bytes while peer-peer with IPv6 had the lowest throughput ranging from 79Mbps for 128 Bytes packet and 335 Mbps for 1408 Bytes packet. For UDP, the highest throughput is achieved again by client-server with IPv4. The bandwidth ranged from 88 Mbps at packet size of 128 Bytes to 808 Mbps for 1408 Bytes and the lowest throughput is that of peer-peer with IPv6, with the lowest of 77 Mbps at packet size of 128Bytes and 403 Mbps for packet size of 1408 Bytes.