Db2 and network communication

The Db2 data server products can communicate by using both wide area networks (WANs) and local area networks (LANs).

WAN
A wide area network generally supports the enterprise servers such as Db2 for z/OS; they require either Transmission Control Protocol/Internet Protocol (TCP/IP) or Systems Network Architecture (SNA).
LAN
A local area network generally supports smaller servers, which requires TCP/IP.