Martian TCs in mgmt VLAN

[Andrii Oliinyk]

I'm beating my head of table trying to understand why i have RPVST TCs in the VLAN having no physical ports assigned (it's only for mgmt SVIs on the switches) except those trunking it between switches. it happens constantly on the single interconnect between core & access switch interconnected with LACP PC. & for every TC in the VLAN both core & access switch are pointing each to other as source of TC. I could assume it's possible when particular inter-switch link goes UP but i have rock-stable all inter-switch links incl. this particular...

[pieterh]

you have a PC with multiple connections to the network configured for LACP?
did you configure this/both link as access port ? if not the PC may forward the incomming LACP packets from link-1 to link-2

[Andrii Oliinyk]

each PC (interswitch link) is p2p link. all interswitch links are trunks with all VLANs allowed.
not sure how LACP mode influence RPVST comparing to PAgP or even dumb mode