DES-7200 Configuration Guide Chapter 10 MSTP Configuration
10-16
psses through a device in a region starting from the region root bridge until it is
0, which means the BPDU message is timeout. A device will discard the BPDU
message whose hop count is 0.
In order to be compatible with the STP protocol and the RSTP protocol out a
region, the MSTP protocol still remains the Message age and Max age
mechanisms.
10.1.2.5 Compatibility of MSTP with
RSTP and STP
For the STP protocol, the MSTP protocol will send the STP BPDU to be
compatible with it like the RSTP protocol. For detailed information, refer to the
Compatibility of RSTP and STP section.
For the RSTP protocol, it will process the CIST part of the MSTP BPDU, so it is
not necessary for the MSTP to send the RSTP BPDU to be compatible with it.
Each device that runs the STP or RSTP protocol is an independent region, and
does not form the same region with any other device.
10.2 Overview of Optional
Features of MSTP
10.2.1 Understanding
Port Fast
If a port of a device is connected with the network terminal directly, this port can
be set as the Port Fast to forward packets directly. The port does not need to
wait 30 seconds before forwarding packets, which is the case when the port is
not set to Port Fast. The following figure indicates which ports of a device can
be set to Port Fast.