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Any configuration changes made locally on the switch won't be synchronized with Sophos Central. We recommend making changes from the Sophos Central control panel instead.

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https://docs.sophos.com/nsg/switch/help/en-us/index.html?contextId=user-guide-features-configure-STP-cist-port-settings

CIST port settings

A Common Spanning Tree connects all adjacent Multiple Spanning Tree regions and acts as a bridge node for communication between STP bridges and LAN segments. The CIST port settings tab shows the Common and Internal Spanning Tree (CIST) settings.

You can see the following settings for each port:

  • Port: The port to which the CIST settings apply.
  • Priority: The port's priority. The lowest priority is the root bridge.
  • Path cost configuration and operation: The relative cost of sending spanning-tree traffic through the port to adjacent bridges within a spanning-tree region.
  • Designated root bridge: The priority of the root bridge and its MAC address.

You can select additional information to show on the CIST port settings tab. Click the ellipsis Ellipsis. and select the options you want to show. You can select from the following options:

  • External root cost: The relative cost of the path to the root bridge.
  • Regional root bridge: The priority, relative cost, and MAC address of the regional root bridge.
  • Designated root bridge: The priority of the root bridge and its MAC address.
  • Edge port configuration/operation: Shows whether the port is configured as an edge port and whether it's in operation. Edge ports are usually connected to endpoint computers or servers. When the network topology changes, edge ports can bypass the listening and learning state and change their STP state directly from blocking to forwarding, speeding up spanning tree generation.

  • P2P MAC configuration/operation: Shows the status of the Point-to-Point (P2P) link and whether it's in operation. P2P links are ports connected to other network devices. For faster convergence, if the port of the P2P link is elected as the root port or the designated port, it can change its STP state directly to forwarding, speeding up spanning tree generation. You'll see one of the following settings:

    • Auto: The switch automatically checks if the port is connected to a P2P link and then sets the status.
    • Yes: The port is connected to a P2P link.
    • No: The port isn't connected to a P2P link.

  • Port role: Shows the port's STP role.

  • Port state: Shows the port's STP state.
  • Port status: Shows whether the port is On or Off.
  • BPDU guard: Shows whether BPDU guard is On or Off.
  • Root guard: Shows whether Root guard is On or Off.
  • BPDU forward: Shows whether BPDU forwarding is On or Off.

To configure port settings, select the ports you want to configure and click Edit. Select the settings you want and click Apply.

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