Configure SVI & Auto-State Behaviour
When we have to gain the capability on any SVI logical interface between bridging function and Routing function on any VLAN, we should configure SVI on switch. The SVI acts as a default gateway for a VLAN.
When you configure SVI on switch, it will come UP only when it as atleast one Port as access or trunk and in STP forwarding state. And if all port allocated to the VLAN goes down, the SVI goes down state.
This behavior can be flipped based on SVI autostate behaviour.
SVI Autostate Exclude: This feature is used to exclude any specific ports or port channel while defining the SVI status UP or down. Let’s say even any port or port-channel is UP state and rest port are down in same VLAN, by SVI Autostate feature, we can make SVI state to Down.
This SVI autostate feature can be configured on any Ethernet port or port channel, it can also be used to exclude any VLAN from autostate excluded interface.
This Auto state disable feature can also keep SVI UP even though any port on those VLAN is not UP. This feature is mostly used when this VLAN is used as Management interface
The Below example shows how to exclude a port from VLAN Interface link-UP calculation: