ZyXEL NetAtlas User Guide - Page 71

Chapter 5 View On each bridge, the root port is the port through which this bridge communicates with the root. It is the port on this switch with the lowest path cost to the root (the root path cost). If there is no root port, then this switch has been accepted as the root bridge of the spanning tree network. For each LAN segment, a designated bridge is selected. This bridge has the lowest cost to the root among the bridges connected to the LAN. 5.4.2 STP Port States STP assigns five port states (see next table) to eliminate packet looping. A bridge port is not allowed to go directly from blocking state to forwarding state so as to eliminate transient loops. Table 28 STP Port States PORT STATE DESCRIPTION Disabled STP is disabled (default). Blocking Only configuration and management BPDUs are received and processed. Listening All BPDUs are received and processed. Learning All BPDUs are received and processed. Information frames are submitted to the learning process but not forwarded. Forwarding All BPDUs are received and processed. All information frames are received and forwarded. 5.4.3 STP/RSTP Status View current STP information in the Spanning Tree Protocol Status screen. Click View > Spanning Tree Protocol Status and select a device from the device list located on the left-hand side of the screen. The fields on the right will display the device's STP information. The screen varies depending on which STP mode (STP, MRSTP or MSTP) you configure on the selected device. NetAtlas EPON Manager User's Guide 71