Information About the Cisco Nexus 2000 Series Fabric Extender
The Cisco Nexus 2000 Series Fabric Extender, also known as FEX, is a highly scalable and flexible server networking solution that works with Cisco Nexus Series devices to provide high-density, low-cost connectivity for server aggregation. Scaling across 1-Gigabit Ethernet, 10-Gigabit Ethernet, unified fabric, rack, and blade server environments, the Fabric Extender is designed to simplify data center architecture and operations.
The Fabric Extender integrates with its parent switch, which is a Cisco Nexus Series device, to allow automatic provisioning and configuration taken from the settings on the parent device. This integration allows large numbers of servers and hosts to be supported by using the same feature set as the parent device, including security and quality-of-service (QoS) configuration parameters, with a single management domain. The Fabric Extender and its parent switch enable a large multipath, loop-free, active-active data center topology without the use of the Spanning Tree Protocol (STP).
The Cisco Nexus 2000 Series Fabric Extender forwards all traffic to its parent Cisco Nexus Series device over 10-Gigabit Ethernet fabric uplinks, which allows all traffic to be inspected by policies established on the Cisco Nexus Series device.
No software is included with the Fabric Extender. The software is automatically downloaded and upgraded from its parent device.
When you configure a Cisco Nexus 2248 port to 100mbps speed (instead of auto-negotiation), FEX does not auto negotiate with the peer. You must manually set the peer not to auto negotiate and set the peer to 100mbps speed.