Flexlink configuration

Flexlink is a fast convergence feature and allows users to configure one of the switchport interface to backup another switchport interface.

Active Interface Configuration
interface GigabitEthernet4/3
switchport
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 100
switchport mode trunk
switchport backup interface Gi4/4

Backup Interface Configuration - Remains the same
interface GigabitEthernet4/4
switchport
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 100
switchport mode trunk

Gig4/3 and Gig4/4 will no longer participate in Spanning-Tree after configuring flexlink.

Verify
show interfaces switchport backup