Dell N3200-ON Networking N-Series Switches User Guide version 6.8.0 - Page 837

on ports that should have a path to the root. The port where the switch received the inferior BPDU is excluded because it already failed; self-looped and designated ports are eliminated as they do not have a path to the root. Figure 21-5. IRC Flow Inferior BDPU received. Are there No other non‐self‐looped non‐designated ports? Yes ‐> Send RLQ query on non‐designated ports. Connectivity to root is lost. Recompute spanning‐tree. Wait for RLQ responses. Negative: Root lost on this port Age‐out the BPDU for this port. Yes No Have received response for every RLQ sent? No Yes: Can still reach root on a port. Yes Connectivity to root still exists - age out port with inferior BPDU. No Have received response for every RLQ sent? Are all RLQ responses negative? No, end processing Upon receiving a negative RLQ response on a port, the port has lost connection to the root and the switch ages-out its BPDU. If all other nondesignated ports received a negative answer, the switch has lost the root and restarts the STP calculation. If the response confirms the switch can still access the root bridge via a particular port, it immediately ages-out the port on which the inferior BPDU was received. If the switch only received responses with a root different from the original root, it has lost the root port and restarts the STP calculation immediately. Spanning Tree Protocol 837