H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 210)

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Devices of some vendors adopt proprietary spanning tree protocols that are similar to RSTP in the way
to implement rapid transition on designated ports. When a device of this kind operating as the upstream
device connects with a WX3000 series device running MSTP, the upstream designated port fails to
change its state rapidly.
The rapid transition feature is developed to resolve this problem. When a WX3000 series device
running MSTP is connected in the upstream direction to a device of another vendor running proprietary
spanning tree protocols, you can enable the rapid transition feature on the ports of the WX3000 series
device operating as the downstream device. Among these ports, those operating as the root ports will
then send agreement packets to their upstream ports after they receive proposal packets from the
upstream designated ports, instead of waiting for agreement packets from the upstream device. This
enables designated ports of the upstream device to change their states rapidly.
Configuring Rapid Transition
Configuration prerequisites
As shown in Figure 22-8 , a WX3000 series device is connected to a device of another vendor. The
former operates as the downstream device, and the latter operates as the upstream device. The
network operates normally.
The upstream device is running a proprietary spanning tree protocol that is similar to RSTP in the way to
implement rapid transition on designated ports. Port 1 is the designated port.
The downstream device is running MSTP. Port 2 is the root port.
Figure 22-8 Network diagram for rapid transition configuration
Configuration procedure
1) Configure the rapid transition feature in system view
Follow these steps to configure the rapid transition feature in system view:
To do… Use the command… Remarks
Enter system view system-view —
Enable the rapid transition feature
stp interface interface-type
interface-number
no-agreement-check
Required
By default, the rapid transition
feature is disabled on a port.
2) Configure the rapid transition feature in Ethernet port view
Follow these steps to configure the rapid transition feature in Ethernet port view: