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	== FEX Discovery and Status Commands ==		== FEX Discovery and Status Commands ==

Admin: Created page with "Category:Wiki == FEX Discovery and Status Commands == === Show FEX Inventory === Displays detected FEX units and their operational state. show fex Example output fields: * FEX number * Description * State (Online, Offline, Configured) * Model * Serial number === Show Detailed FEX Information === show fex detail Includes: * Pinning status * Fabric interfaces * Power state * Host interface count === Show FEX Hardware Invent..."

2025-12-20T17:06:15Z

Created page with "Category:Wiki == FEX Discovery and Status Commands == === Show FEX Inventory === Displays detected FEX units and their operational state. <nowiki> show fex</nowiki> Example output fields: * FEX number * Description * State (Online, Offline, Configured) * Model * Serial number === Show Detailed FEX Information === <nowiki> show fex detail</nowiki> Includes: * Pinning status * Fabric interfaces * Power state * Host interface count === Show FEX Hardware Invent..."

New page

[[Category:Wiki]]

== FEX Discovery and Status Commands ==

=== Show FEX Inventory ===
Displays detected FEX units and their operational state.

<nowiki>
show fex</nowiki>

Example output fields:
* FEX number
* Description
* State (Online, Offline, Configured)
* Model
* Serial number

=== Show Detailed FEX Information ===

<nowiki>
show fex detail</nowiki>

Includes:
* Pinning status
* Fabric interfaces
* Power state
* Host interface count

=== Show FEX Hardware Inventory ===

<nowiki>
show inventory fex</nowiki>

Useful for RMA and asset tracking.

=== Show FEX Environment ===

<nowiki>
show environment fex
</nowiki>

Displays:
* Temperature sensors
* Fan status
* Power supply status

== FEX Association and Configuration ==

=== Configure FEX ID ===

<nowiki>
configure terminal
fex <fex-id>
description Rack-01-FEX</nowiki>

Constraints:
* FEX ID range depends on platform
* ID must match physical FEX

=== Associate Fabric Interfaces ===

<nowiki>
configure terminal
interface ethernet1/1
switchport mode fex-fabric
fex associate <fex-id></nowiki>

Best practices:
* Use port-channel for redundancy
* Avoid mixing fabric and non-fabric interfaces

=== Fabric Port-Channel Configuration ===

<nowiki>
configure terminal
interface port-channel10
switchport mode fex-fabric
fex associate <fex-id></nowiki>

=== Verify Fabric Pinning ===

<nowiki>
show fex pinning</nowiki>

Shows:
* Host interface to fabric interface mapping
* Load distribution

== Host Interface Commands ==

=== Configure Host Interface Range ===

<nowiki>
configure terminal
interface ethernet101/1/1
description Server01-NIC1
switchport
switchport mode access
switchport access vlan 100
spanning-tree port type edge</nowiki>

Notes:
* FEX host interfaces do not support L3
* All switching logic is handled by parent switch

=== Host Interface Port-Channel (vPC not supported on host ports) ===

<nowiki>
configure terminal
interface port-channel20
switchport
switchport mode trunk</nowiki>

== VLAN and Trunking Behavior on FEX ==

=== VLAN Assignment ===

<nowiki>
show vlan fex</nowiki>

Displays VLANs allowed and active per FEX.

=== Trunk Configuration on Host Interface ===

<nowiki>
configure terminal
interface ethernet101/1/2
switchport mode trunk
switchport trunk allowed vlan 100,200,300</nowiki>

Restrictions:
* No dynamic trunk negotiation
* VLANs must exist on parent switch

== Security Concepts and Commands ==

=== FEX Trust Boundary ===
FEX operates as a remote line card:
* No local control plane
* No independent security policies

=== Port Security on Host Interfaces ===

<nowiki>
configure terminal
interface ethernet101/1/3
switchport port-security
switchport port-security maximum 2
switchport port-security violation restrict</nowiki>

=== DHCP Snooping ===

<nowiki>
configure terminal
ip dhcp snooping
ip dhcp snooping vlan 100
interface ethernet101/1/4
ip dhcp snooping trust</nowiki>

=== Dynamic ARP Inspection ===

<nowiki>
configure terminal
ip arp inspection vlan 100</nowiki>

Note:
* Requires DHCP snooping
* Enforced at parent switch

=== BPDU Guard ===

<nowiki>
configure terminal
interface ethernet101/1/5
spanning-tree bpduguard enable</nowiki>

== Monitoring and Performance ==

=== Show Interface Status ===

<nowiki>
show interface ethernet101/1/1</nowiki>

=== Show Interface Counters ===

<nowiki>
show interface counters</nowiki>

=== Show FEX Statistics ===

<nowiki>
show fex statistics</nowiki>

Includes:
* Packet drops
* Errors
* Fabric utilization

== FEX High Availability and Redundancy ==

=== Dual-Homed FEX (vPC) ===

<nowiki>
show fex
show vpc</nowiki>

Key concepts:
* FEX is dual-attached to two parent switches
* Uses vPC domain for redundancy
* Control plane remains on parents

=== Verify FEX vPC Status ===

<nowiki>
show fex detail | include vPC</nowiki>

== Software and Compatibility ==

=== Show FEX Image Version ===

<nowiki>
show fex version</nowiki>

FEX image is automatically downloaded from parent switch.

=== Compatibility Check ===

<nowiki>
show compatibility fex</nowiki>

Ensures:
* NX-OS version compatibility
* Hardware support

== FEX Troubleshooting ==

=== FEX Not Coming Online ===

Check:
<nowiki>
show fex
show logging | include FEX</nowiki>

Common causes:
* Incorrect FEX ID
* Unsupported NX-OS version
* Fabric ports not in fex-fabric mode

=== Host Interfaces Down ===

<nowiki>
show interface ethernet101/1/1 status
show fex pinning</nowiki>

Possible reasons:
* Fabric port failure
* VLAN mismatch
* Server NIC down

=== Fabric Port Issues ===

<nowiki>
show interface ethernet1/1
show interface port-channel10</nowiki>

Check for:
* Errors
* Speed/duplex mismatch
* Incorrect port-channel config

=== VLAN Not Passing Traffic ===

<nowiki>
show vlan id 100
show interface trunk</nowiki>

Ensure:
* VLAN allowed on trunk
* VLAN active on parent switch

== Useful Links ==

* Cisco Nexus Fabric Extender Configuration Guide
https://www.cisco.com/c/en/us/support/switches/nexus-2000-series-fabric-extenders/products-installation-and-configuration-guides-list.html

* Cisco Nexus 2000 Series Data Sheet
https://www.cisco.com/c/en/us/products/switches/nexus-2000-series-fabric-extenders/index.html

* Cisco NX-OS Command Reference
https://www.cisco.com/c/en/us/support/ios-nx-os-software/nx-os-software/products-command-reference-list.html

* Cisco Validated Designs – Data Center
https://www.cisco.com/c/en/us/solutions/design-zone/data-center-design-guides.html

CISCO-IOS - FEX Commands - Revision history

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