With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
vrtlIntrPortNum
vrtl Intr Port Num
1.3.6.1.4.1.351.110.5.2.8.1.1.1.2
Port number which will be connected to the Virtual Interface. Value zero meens that this virtual interface is not connected to any port.
Back to CISCO-MGX82XX-VIRTUAL-PORT-MIB MIB page.
IPHost Network monitor allows you to monitor vrtlIntrPortNum 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.