What is FEX?

FEX, which likely stands for Fabric Extender, is a technology used in networking, particularly in Cisco environments. It extends the capabilities of a parent switch (also known as a Nexus switch in Cisco's terminology) by providing a distributed line card architecture. FEX essentially acts as a remote line card, simplifying network management and allowing for a higher port density without increasing the complexity of the core switching infrastructure. It simplifies the management of a large number of ports and reduces cabling complexity, making it easier to manage large data centers.