20-43z The rapid transition feature can be enabled on only root ports or alternate ports.z If you configure the rapid transition feature on a designated port, the feature does not take effect onthe port.Configuring VLAN-VPN TunnelIntroductionThe VLAN-VPN Tunnel function enables STP packets to be transparently transmitted betweengeographically dispersed customer networks through specified VLAN VPNs in service providernetworks, through which spanning trees can be generated across these customer networks and areindependent of those of the service provider network.As shown in Figure 20-9, the upper part is the service provider network, and the lower part comprisesthe customer networks. The service provider network comprises packet input/output devices, and thecustomer network has networks A and B. On the service provider network, configure the arriving STPpackets at the input device to have MAC addresses in a special format, and reconvert them back to theiroriginal formats at the output device. This is how transparent transmission is implemented over theservice provider network.Figure 20-9 VLAN-VPN tunnel network hierarchyNetworkNetwork A Network BCustomer networksService provider networkPacket input/outputdevicePacket input/outputdeviceConfiguring VLAN-VPN tunnelFollow these steps to configure VLAN-VPN tunnel:To do... Use the command... RemarksEnter system view system-view —Enable MSTP globally stp enable —
