1-22To do... Use the command... RemarksEnter system view system-view —Configure the MSTP operationmode stp mode { stp | rstp | mstp }RequiredAn MSTP-enabled switchoperates in the MSTP mode bydefault.Configuration example# Specify the MSTP operation mode as STP-compatible. system-view[Sysname] stp mode stpConfiguring the Maximum Hop Count of an MST RegionThe maximum hop count configured on the region root is also the maximum hops of the MST region.The value of the maximum hop count limits the size of the MST region.A configuration BPDU contains a field that maintains the remaining hops of the configuration BPDU.And a switch discards the configuration BPDUs whose remaining hops are 0. After a configurationBPDU reaches a root bridge of a spanning tree in an MST region, the value of the remaining hops fieldin the configuration BPDU is decreased by 1 every time the configuration BPDU passes one switch.Such a mechanism disables the switches that are beyond the maximum hop count from participating inspanning tree calculation, and thus limits the size of an MST region.With such a mechanism, the maximum hop count configured on the switch operating as the root bridgeof the CIST or an MSTI in an MST region becomes the network diameter of the spanning tree, whichlimits the size of the spanning tree in the current MST region. The switches that are not root bridges inthe MST region adopt the maximum hop settings of their root bridges.Configuration procedureFollow these steps to configure the maximum hop count for an MST region:To do... Use the command... RemarksEnter system view system-view —Configure the maximum hopcount of the MST region stp max-hops hopsRequiredBy default, the maximum hopcount of an MST region is 20.The bigger the maximum hop count, the larger the MST region is. Note that only the maximum hopsettings on the switch operating as a region root can limit the size of the MST region.Configuration example# Configure the maximum hop count of the MST region to be 30. system-view[Sysname] stp max-hops 30
