VSX and MSTP loop-protect configurations (physical and logical views)

The figures in this topic show the physical and logical views for VSX and MSTP loop-protect configurations with MSTP as the default instance.

Figure 13: Physical view of the VSX and MSTP loop-protect configurations

The configuration from the previous figure is shown in its logical view, so that you can see how the network views the configuration. For example, the following figure shows that the VSX distributed pair as one switch. The ports on Agg-2 are blocking traffic. The logical view in the next figure shows that the traffic is distributed so that the traffic continues to flow.

Figure 14: Logical view of the VSX and MSTP loop-protect configurations

STP interoperability with Loop-Protect in VSX

When both loop protect and STP are enabled on the switch:

• If switch first detects STP, STP blocks the port to stop the loop and loop protect feature will not come into effect.

• If switch first detects loop protect, loop protect blocks the port to stop the loop and STP will not take any effect as there are no loops.

• If loop protect has re-enable timer enabled, the port will be unblocked once the timer is expired. In this case, whichever protocol detects the loop first will block the port.