With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
vtpOutSubsetAdverts
vtp Out Subset Adverts
1.3.6.1.4.1.9.9.46.1.5.1.1.5
The total number of VTP Subset Adverts sent for this management domain.
Back to CISCO-VTP-MIB MIB page.
IPHost Network monitor allows you to monitor vtpOutSubsetAdverts on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.