Hello@user_3423639
The network diameter indicates the length of the path that comprises the maximum number of switches and is represented by the number of the switches on the path. The network diameter is a parameter indicating the network size. The larger the network diameter, the larger the network size. The setting of the network diameter affects only the CIST and does not affect the MSTI. After you set the network diameter for a switch, the MSTP performs the automatic calculation and set Forward Delay, Hello Time, and Max Age to the optimal values