"Gruher, Joseph R" wrote: >11:35:06.873861 STP 802.1d, Config, Flags [Topology change], bridge-id 8001.c8:4c:75:e8:f5:00.8001, length 43 >11:35:08.874054 STP 802.1d, Config, Flags [Topology change], bridge-id 8001.c8:4c:75:e8:f5:00.8001, length 43 There's a good hint that STP is involved !