Loop Protection

The Loop Protection page is available only when there are one or more switches in the inventory. Instant On devices use two mechanisms for loop protection:

Aruba Proprietary Mechanism

This mechanism is in-built on AP11D and AP22D access points to protect them against loops or storms. This mechanism cannot be disabled on the device using the Instant On web application. The device sends out a proprietary packet and blocks any port that receives the same packet. The device will recover in 60 seconds once the fault is removed.

Rapid Spanning Tree Protocol (RSTP)

This mechanism is available only on the Instant On switches and is compliant with the 802.1w standard. RSTP provides loop protection in an interoperable environment with third-party networking equipment.

The RSTP mechanism can be enabled or disabled on the network using the Instant On web application. When this mechanism is enabled, probe packets are sent out every 2 seconds from the root bridge device. If the same packet is seen in more than one port of a downstream device, it indicates that a loop in the network exists, and RSTP will block ports to create a loop-free topology.

Follow these steps to enable RSTP on the network:

  1. Click the Devices () tile on the Instant On web application home page or click Devices from the navigation pane on the left.
  2. Click the Loop Protection tab.
  3. Click the Rapid Spanning Tree (RSTP) checkbox to enable loop protection on the network. The page lists the spanning tree diagnostics such as the Root Bridge Device connected to the network and its Priority value. It also indicates the duration and number of times the Topology changed for the root bridge device on the network.

RSTP is enabled by default when a stack is present in the device inventory and and the checkbox selection cannot be disabled. However, if the stack is removed from the inventory, RSTP will still be enabled, but the checkbox becomes available to enable or disable the setting.

Bridge Priority Assignments

The Bridge Priority page displays the participating spanning tree devices and their bridge priority. The priority will be automatically determined using the topology and the position of the devices related to each other. The root bridge is assigned to the Instant On switch or router that is closest to the internet router or entry point to a private network. The root bridge priority is assigned the default value of 32768. All subsequent Instant On switches and routers are assigned priority values based on their distance from the root bridge.

For example, a network with three Instant On devices can have the following priority assignments:

  • Instant On 1 would be assigned priority 32768 (root)
  • Instant On 2 would be assigned priority 36864
  • Instant On 3 would be assigned priority 40960

To view the bridge priority details and modify the base priority, follow these steps:

  1. Click the Devices () tile on the Instant On web application home page or click Devices from the navigation pane on the left.
  2. Click the Loop Protection tab.
  3. Click the Rapid Spanning Tree (RSTP) checkbox to enable loop protection. The details of the Base priority and Root bridge are displayed.
  4. Under Priority Assignment, click the drop-down arrow and select a priority from the Base Priority list.
  5. If you choose to recalculate the bridge priority, click the Recalculate button next to Priority Assignment and then click Recalculate Priorities.

    The changes are auto saved.