1.1.f RPVST+

Lab Setup

Shut down all interfaces that are not shown
Configure all the interfaces shown as access links in VLAN 12.
On each switch, configure the bridge priority for VLAN 12 as shown.
Switch ports should be root (R), designated (D), or blocking (B), as shown
Assign IP addresses as shown below.
Configure ntp server 10.1.12.1 on all devices, except R1.
On R1, configure ntp master 4.

Task 1
Configure only the following switches to operate in rapid-pvst mode: SW1 SW3 SW4

Task 2
Use debug output to explain how RSTP achieves rapid convergence when SW3 loses its root port.
Shut down SW3’s F0/23 port and SW4’s F0/21 port to simplify the problem.
Verify that SW3’s F0/21 and SW4’s F0/23 are root ports.
Verify that SW3’s F0/19 is a designated port and SW4’s F0/19 is in discarding (blocking) state.
On SW3 and SW4, enter the following commands:
clear logging
debug spanning-tree events
debug spanning-tree synchronization
Shut down SW3’s F0/21 port and observe the logs on these three switches.

Task 3
Use debug output to demonstrate the RSTP convergence process as SW3’s F0/21 returns to its role as root port, SW3 F0/19 transitions from root port back to designated port, and SW4’s F0/19 transitions from designated port back to discarding.

Clear the logs on SW1, SW3, and SW4 and verify spanning-tree debugging is enabled on these switches.

no shut (activate) SW3 F0/21 and analyze the results.

Task 4
Use debug output to demonstrate the importance of link type in RSTP convergence.
On both SW3 and SW4:
Clear the logs.
Verify spanning-tree debugging is enabled.
Configure the shared link type for F0/19.
Shut down SW3 F0/21 and observe the result.

Task 5
Using debug output, explain how RSTP switches interoperate with switches in legacy, 802.1D mode.
Reactivate F0/21 on SW3 and remove the link-type commands from F0/19 on SW3 and SW4.
Clear the logs on SW3 and SW4 and verify spanning-tree debugging.
Enter the following commands on SW2:
clear logging
debug spanning-tree events
debug spanning-tree synchronization
Reactivate SW3’s interface F0/23 and observe the result.

Clear the logs on SW2, reactivate SW4’s interface F0/21, and observe the result.
Recall that SW2 is in the default PVST mode.

Task 6
In your final RSTP lab task, enable SW2 for RSTP mode. Make sure that none of the edge ports flap when the switched infrastructure reconverges. Use debugging output on SW2 to explain your results.
Shut down SW2 interfaces F0/21 and F0/23.
Enable the required RSTP configurations.
Clear the logs on SW2.
Reactivate SW2 interfaces F0/21 and F0/23 at the same time and observe the results.