With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
alL2tpStatsActiveTunnels
ALTIGA L2tp Statistics Active Tunnels
1.3.6.1.4.1.3076.2.1.2.16.1.7
This object returns the number of tunnels that are currently active.
Back to ALTIGA-L2TP-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor alL2tpStatsActiveTunnels 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.