By default, Spanning Tree is Disabled. If Enabled, the Switch will listen for BPDU packets and its accompanying Hello packet. BPDU packets are sent even if a BPDU packet was not received. Therefore, each link between bridges is sensitive to the status of the link. Ultimately this difference results in faster detection of failed links, and thus faster topology adjustment. A
After Enabling STP, setting the STP Global Setting includes the following options:
Bridge Priority: This value between 0 and 65535 specifies the
priority for forwarding packets: the lower the value, the higher the priority. The default is 32768.
Bridge Max Age: This value may be set to ensure that old information does not endlessly circulate through redundant paths in the network, preventing the effective propagation of the new information. Set by the Root Bridge, this value will aid in determining that the Switch has spanning tree configuration values consistent with other devices on the bridged LAN. If the value ages out and a BPDU has still not been received from the Root Bridge, the Switch will start sending its own BPDU to all other switches for permission to become the Root Bridge. If it turns out that the Switch has the lowest Bridge Identifier, it will become the Root Bridge. A time interval may be chosen between 6 and 40 seconds. The default value is 20.
Bridge Hello Time: The user may set the time interval between transmissions of configuration messages by the root device, thus stating that the Switch is still functioning. The default is 2 seconds. (Max Age has to have a value bigger than Hello Time)
Bridge Forward Delay: This sets the maximum amount of time that the root device will wait before changing states. The default is 15 seconds.
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