With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
alL2tpStatsFailedSessions
ALTIGA L2tp Statistics Failed Sessions
1.3.6.1.4.1.3076.2.1.2.16.1.10
This object returns the number of sessions that failed to reach the established state for this tunnel domain.
Back to ALTIGA-L2TP-STATS-MIB MIB page.
IPHost Network monitor allows you to monitor alL2tpStatsFailedSessions 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.