What is the behavior a PVST environment when a router "sub-interface" configured with a particular VLAN is shutdown/brought up. The router connects to a c2950 dot1Q trunk port configured for few VLANs.
When there's a change of the physical interface state(up/down) I see the STP state transition. However the change of status of sub-interface has no impact on STP status of the connected switch interface(remains in forwarding even for the disabled VLAN).
How is this behavior explained? Have I overlooked something here?
Thanks in advance for your time/thoughts.