Water-utility NSX-T overlay on a VLAN goes silent after a spanning-tree reconvergence. The LAN team reports that VLAN in a Blocking state on the ToR toward the transport nodes. Distributed Firewall configuration is unchanged. What should the administrator do?
Select an answer to reveal the explanation.
Short Explanation
Spanning tree is the traffic cop on the copper. If it puts the NSX VLAN in Blocking, overlay packets never leave the parking lot and DFW looks guilty. Get LAN to restore Forwarding on that VLAN; publishing another DFW section will not unblock STP.
Full Explanation
Physical switching control-plane events such as spanning-tree Blocking on the VLAN used by NSX-T overlay or management stop underlay forwarding even when NSX security configuration is valid. Distributed Firewall publishes, identity firewall, and Carbon Black Cloud isolation do not change STP state. Engage LAN engineers to correct port roles, root placement, or VLAN allow-lists so the NSX VLAN returns to Forwarding, then recheck TEP and Manager connectivity.