With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cpvlanPrivatePortTable
cpvlan Private Port Table
1.3.6.1.4.1.9.9.173.1.2.1
A table containing information of the configuration of secondary VLAN on the ports of the device.
Back to CISCO-PRIVATE-VLAN-MIB MIB page.
IPHost Network monitor allows you to monitor cpvlanPrivatePortTable on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.