Differences

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--- networking:stp [2025/12/03 15:51] – [PORT-FAST] v1ctor
+++ networking:stp [2025/12/03 16:11] (current) – [Root Guard] v1ctor
@@ Line 38: / Line 38: @@
 ==== PORT-FAST ====
-When port flaps, switch sends TCN (topology change notification) message, which forces all switches to re-calculate the root switch. This is not very efficient when port towards the client flaps. In order to mitigate that, customer facing port is configured with **spanning-tree portfast**.
+When port flaps, switch sends TCN (topology change notification) message, which forces all switches to re-calculate the root switch. This is not very efficient when port towards the client flaps. In order to mitigate that, customer facing port is configured with **spanning-tree portfast**. This port will be always on (forwarding).
+==== BPDU Guard ====
+We should not receive BPDUs on the customer facing ports. There is a feature which sets the port to **err-disabled** state if switch receives a BPDU on that port.
+==== Root Guard ====
+Configuration on the Root switch to protect hijacking the Root role. Configured on the ports.
+==== MSTP ====
+Instead of sending BPDU for each VLAN, MSTP aggregates VLANs into the instances and send a single BPDU for that group.
+On Arista, by default MST instance 0 is created and all VLANs belong to that instance.