Consider the following commands executed on a Layer 3 switch named switchA:
Which of the following physical interfaces do NOT affect the uplink state of VLAN 10? (Choose two.)
The Fa0/2 and Fa0/3 physical interfaces of switchA do not affect the uplink state of VLAN 10. This is because the switchport autostate exclude command is used on the Fa0/2 and Fa0/3 interfaces. This command causes the exclusion of an interface from the determination of the uplink state of the VLAN (SVI interface) to which the interface belongs.
An SVI or switch virtual interface is a logical interface that allows you to enable inter-VLAN routing on Layer 3 switches. SVIs are configured as VLAN interfaces and have at least one physical interface assigned to the VLANs. An SVI is up and running when all of the following conditions are met:
- It is configured on the switch and is enabled in the VLAN database
- It is not in the administratively down state
- It has at least one Layer 2 (access or trunk) interface in the up state
When an SVI services multiple interfaces (the switch ports in the VLAN to which the SVI connects) and all of them go down, the SVI also goes down by default. When any of the interfaces comes up, the SVI also comes up. By default, all interfaces assigned to the SVI are involved in determining its uplink state. However, if you do not want a particular interface to participate in this determination, use the switchport autostate exclude command on that interface.
You can use the switchport autostate exclude command on any Layer 2 access or trunk interface. This command applies to all VLANs to which the interface belongs. If the excluded interface of an SVI is in the up state and all the other interfaces of the SVI are in the down state, the SVI remains in the down state. The state of the SVI does not change to up.
The Fa0/1 and Fa0/4 interfaces of switchA affect the uplink state of VLAN 10 because all the interfaces assigned to an SVI contribute towards the uplink state determination of the SVI by default.
Layer 2 Technologies
Configure and verify VLANs