Test steps
- Create two tagged streams of VLAN ID 20 with source port 3, and destination port 1 and port 2.
- Ensure that the VLAN 20 traffic from port 3 is going through the N5K1 since this is the common spanning tree root bridge. The interface counters on N5K2 Port 1 and Port 2 should read 0. The only interface on N5K2 that should be incrementing should be the internal vPC channel, and the Port 3 transmit counter.
- To simulate a failover scenario, shut down Port-channel 100 on N5K1 and check for any traffic disruption.
- Recover Po100 on N5K1 and ensure that N5K1 becomes the root bridge.
- Shut down individual port 9 and port 8 on S4128-SW1 switch, and check for any traffic disruptions. The traffic should switch-over to Po110 on the S4128-SW2 switch and continue without measurable disruption.
- Recover port 9 and port 8 and check for any measurable traffic disruption.
Results
With RSTP and MST enabled, considering that MST uses RSTP convergence timers, and only a single spanning tree instance running between the two different regions, we should expect to get great convergence times.