do not forget to remove vlan authentication(otherwise it does not work by link down/up events for transit connections!)
Code: Select all
vlan 10-30 authentication disable
Code: Select all
vlan 10-30 authentication disable
The STP loop guard provides additional protection against Layer 2 STP loops. When enabled it ensures that The actual function of Loop guard is to protect non designated ports (Alternate, Backup or Root ports) when they fail to receive (usually) two BPDU in a row. The port is moved into the protected mode instead of the listening/learning/forwarding state. In this mode the port is not impacted by a topology change notification that may arise in the network - thus preventing loops.
A port exits the protected mode when:
• Loop guard is disabled on the port (or globally)
• The port is down (admin down or link down).
• The port starts receiving BPDUs
• Any configuration changes that affect spanning tree on this port
Note:
• Loop Guard cannot be configured on ports that are also Root Guard enabled
The root guard is mutually exclusive with the loop guard. The root guard is used on designated ports, and it does not allow the port to become non-designated. The loop guard works on non-designated ports and does not allow the port to become designated through the expiration of max_age.