stp no-agreement-check
Function
The stp no-agreement-check command configures the common fast transition mechanism on an interface.
The undo stp no-agreement-check command restores the default fast transition mechanism on an interface.
By default, the enhanced transition mechanism is configured on an interface.
Usage Guidelines
Usage Scenario
Running the stp no-agreement-check command configures a common fast transition mechanism on a port.
Running the undo stp no-agreement-check command configures an enhanced fast transition mechanism on a port.
Precautions
- Enhanced mode: The current interface counts a root port when it
calculates the synchronization flag bit.
An upstream device sends a Proposal message to a downstream device requesting fast status transition. After receiving the message, the downstream device sets the port connected to the upstream device as the root port and blocks all non-edge ports.
The upstream device then sends an Agreement message to the downstream device. After the downstream device receives the message, the root port transitions to the Forwarding state.
The downstream device then responds with an Agreement message. After receiving the message, the upstream device sets the port connected to the downstream device as the designated port, and then the status of the designated port changes to Forwarding.
- Common mode: The current interface ignores the root port when
it calculates the synchronization flag bit.
An upstream device sends a Proposal message to a downstream device requesting fast transition. After receiving the message, the downstream device sets the port connected to the upstream device as the root port and blocks all non-edge ports. Then, the status of the root port changes to Forwarding.
The downstream device then responds with an Agreement message. After receiving the message, the upstream device sets the port connected to the downstream device as the designated port, and then the status of the designated port changes to Forwarding.
Between two interconnected switching devices in a spanning tree, the switching device nearer to the root bridge is the upstream device of the other devices.
