Fabric Extender Features; Layer 2 Host Interfaces - Cisco Nexus 5000 Series Configuration Manual

Configuring the Fabric Extender
• Port channel fabric interface—A port channel uplink connection from the Fabric Extender to its parent
• Host interface—An Ethernet host interface for connection to a server or host system.
• Port channel host interface—A port channel host interface for connection to a server or host system.

Fabric Extender Features

The Cisco Nexus 2000 Series Fabric Extender allows a single switch—and a single consistent set of switch
features—to be supported across a large number of hosts and servers. By supporting a large server-domain
under a single management entity, policies can be enforced more efficiently.
Some of the features of the parent switch cannot be extended onto the Fabric Extender.

Layer 2 Host Interfaces

The Fabric Extender provides connectivity for computer hosts and other edge devices in the network fabric.
The following guidelines should be followed when connecting devices to Fabric Extender host interfaces:
• All Fabric Extender host interfaces run as spanning tree edge ports with BPDU Guard enabled and cannot
• Servers utilizing active/standby teaming, 802.3ad port channels, or other host-based link redundancy
• Any device running spanning tree connected to a Fabric Extender host interface will result in that host
• Any edge switch that leverages a link redundancy mechanism not dependent on Spanning Tree such as
You can enable host interfaces to accept Cisco Discovery Protocol (CDP) packets. This protocol only works
when it is enabled for both ends of a link.
CDP is not supported on fabric interfaces when the Fabric Extender is configured in a virtual port channel
Note
(vPC) topology.
A fabric interface includes the corresponding interface on the parent switch. This interface
Note
is enabled when you enter the switchport mode fex-fabric command.
switch. This connection consists of fabric interfaces bundled into a single logical channel.
Do not connect a bridge or switch to a host interface. These interfaces are designed to
Note
provide end host or server connectivity.
be configured as Spanning Tree network ports.
mechanisms can be connected to Fabric Extender host interfaces.
interface being placed in an error-disabled state when a BPDU is received.
Cisco Flexlink or vPC (with BPDUFilter enabled) may be connected to a Fabric Extender host interface.
Since spanning tree is not utilized to eliminate loops, care must be taken to ensure a loop-free topology
below the Fabric Extender host interfaces.
Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N1(1)

Fabric Extender Features

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