Fabric Interface Features; Host Interfaces; Layer 3 Host Interfaces; Layer 2 Host Interfaces - Cisco SD2008T-NA Configuration Manual

Overview

Fabric Interface Features

The FEX fabric interfaces support static port channels. During the initial discovery and association process,
SFP+ validation and digital optical monitoring (DOM) are performed as follows:
• The FEX performs a local check on the uplink SFP+ transceiver. If it fails the security check, the LED
• The FEX local check is bypassed if it is running its backup image.
• The parent switch performs SFP validation again when the fabric interface is brought up. It keeps the
Once an interface on the parent switch is configured in fex-fabric mode, all other features that were configured
on that port and are not relevant to this mode are deactivated. If the interface is reconfigured to remove
fex-fabric mode, the previous configurations are reactivated.
For more information about PFC, see the Cisco Nexus 7000 Series NX-OS Quality of Service Configuration
Guide.

Host Interfaces

Layer 3 Host Interfaces

Beginning with Cisco NX-OS Release 5.2, by default, all host interfaces on a Fabric Extender connected to
a Cisco Nexus 7000 Series parent switch run in Layer 3 mode.
If you have updated the parent switch to Cisco Nexus Release 5.2, previously configured Fabric Extender
Note
host interfaces retain their default port mode, Layer 2. You can change these ports to Layer 3 mode with
the no switchport command.
The host interfaces also support subinterfaces. You can create up to 32 subinterfaces on a Fabric Extender
host interface.
For information about interfaces and subinterfaces, see the Cisco Nexus 7000 Series NX-OS Interfaces
Configuration Guide.

Layer 2 Host Interfaces

In Cisco NX-OS Release 5.1 and earlier releases, the default port mode is Layer 2.
To run a host interface in Layer 2 mode, use the switchport command. For Cisco NX-OS Release 5.2 and
later releases, to change the port mode to Layer 3, use the no switchport command.
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
OL-25816-02
flashes but the link is still allowed to come up.
fabric interface down if SFP validation fails.
be configured as spanning tree network ports.
Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide

Fabric Interface Features

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