dot1dStpTimeSinceTopologyChange
dot1d Stp Time Since Topology Change
1.3.6.1.2.1.17.2.3
The time (in hundredths of a second) since the last time a topology change was detected by the bridge entity.
Back to rfc1493 MIB page.
IPHost Network monitor uses SNMP for monitoring health and availability of devices and applications in your network. You can send a SNMP Set to any remote device to monitor a specific SNMP object (CPU, Memory, Disk, Server Temperature, RAID failures, IO statistics, connection counts, error and much more).