With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
vmPortStatus
vm Port Status
1.3.6.1.4.1.9.9.68.1.2.2.1.3
An indication of the current VLAN status of the port. A status of inactive(1) indicates that a dynamic port does not yet have a VLAN assigned, or a port is assigned to a VLAN that is currently not active. A status of active(2) indicates that the currently assigned VLAN is active. A status of shutdown(3) indicates that the port has been disabled as a result of VQP shutdown response.
Back to CISCO-VLAN-MEMBERSHIP-MIB MIB page.
IPHost Network monitor allows you to monitor vmPortStatus on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.