3Com 2928 User Guide - Page 224

Figure 1-8 Configure MSTP globally Table 1-9 describes the configuration items of configuring MSTP globally. Table 1-9 Configuration items of configuring MSTP globally Item Enable STP Globally BPDU Guard Mode Max Hops Path Cost Standard Description Select whether to enable STP globally. Other MSTP configurations take effect only after you enable STP globally. Select whether to enable BPDU guard BPDU guard can protect the device from malicious BPDU attacks, thus making the network topology stable. Set the working mode of STP, which can be STP, RSTP, or MSTP. z STP: Each port on a device sends out STP BPDUs. z RSTP: Each port on a device sends out RSTP BPDUs, and automatically migrates to STP-compatible mode when detecting that it is connected with a device running STP. z MSTP: Each port on a device sends out MSTP BPDUs, and automatically migrates to STP-compatible mode when detecting that it is connected with a device running STP. The working mode is RSTP by default. Set the maximum number of hops in an MST region to restrict the region size. The setting can take effect only when it is configured on the regional root bridge. Specify the standard for path cost calculation. It can be Legacy, IEEE 802.1D-1998, or IEEE 802.1T. 1-17