Configuration Prerequisites; Configuration Procedure - HP FlexFabric 12900 Series Configuration Manual

Figure 25 Rapid state transition of an RSTP designated port
If the upstream device is a third-party device, the rapid state transition implementation might be limited
as follows:
The upstream device uses a rapid transition mechanism similar to that of RSTP.
•
• The downstream device adopts MSTP and does not operate in RSTP mode.
In this case, the following occurs:
1. The root port on the downstream device receives no agreement packet from the upstream device.
2. It sends no agreement packets to the upstream device.
As a result, the designated port of the upstream device can transit to the forwarding state only after a
period twice the Forward Delay.
You can enable the No Agreement Check feature on the downstream device's port to enable the
designated port of the upstream device to transit its state rapidly.

Configuration prerequisites

Before you configure the No Agreement Check function, complete the following tasks:
Connect a device to a third-party upstream device that supports spanning tree protocols through a
•
point-to-point link.
Configure the same region name, revision level, and VLAN-to-instance mappings on the two
•
devices.

Configuration procedure

Enable the No Agreement Check feature on the root port.
To configure No Agreement Check:
Step
1. Enter system view.
2. Enter Layer 2 Ethernet or
aggregate interface view.
3. Enable No Agreement
Check.
Command
system-view
interface interface-type interface-number
stp no-agreement-check
103
Remarks
N/A
N/A
By default, No Agreement
Check is disabled.