Spanning-Tree Auto-Edge; Spanning-Tree Backbonefast - NETGEAR M6100 Series Reference Manual

spanning-tree auto-edge

Use this command to allow the interface to become an edge port if it does not receive any
BPDUs within a given amount of time.
Default Enabled
Format
spanning-tree auto-edge
Mode Interface Config
no spanning-tree auto-edge
This command resets the auto-edge status of the port to the default value.
Format
no spanning-tree auto-edge
Mode Interface Config

spanning-tree backbonefast

Use this command to enable the detection of indirect link failures and accelerate spanning
tree convergence on PVSTP configured switches.
Backbonefast accelerates finding an alternate path when an indirect link to the root port goes
down.
Backbonefast can be configured even if the switch is configured for MST(RSTP) or PVST
mode. It only has an effect when the switch is configured for the PVST mode.
If a backbonefast-enabled switch receives an inferior BPDU from its designated switch on a
root or blocked port, it sets the maximum aging time on the interfaces on which it received the
inferior BPDU if there are alternate paths to the designated switch. This allows a blocked port
to immediately move to the listening state where the port can be transitioned to the
forwarding state in the normal manner.
On receipt of an inferior BPDU from a designated bridge, backbonefast enabled switches
send a Root Link Query (RLQ) request to all non-designated ports except the port from which
it received the inferior BPDU. This check validates that the switch can receive packets from
the root on ports where it expects to receive BPDUs. The port from which the original inferior
BPDU was received is excluded because it has already encountered a failure. Designated
ports are excluded as they do not lead to the root.
On receipt of an RLQ response, if the answer is negative, the receiving port has lost
connection to the root and its BPDU is immediately aged out. If all nondesignated ports have
already received a negative answer, the whole bridge has lost the root and can start the STP
calculation from scratch.
If the answer confirms the switch can access the root bridge on a port, it can immediately age
out the port on which it initially received the inferior BPDU.
A bridge that sends an RLQ puts its bridge ID in the PDU. This ensures that it does not flood
the response on designated ports.
M6100 Series Switches
Switching Commands
332