Every port has to store the information of its best BPDU for MaxAge timer (20 sec by default). This information is always compared to the BPDUs received on this port.
If no BPDU is received, the best BPDU is the one which the brigde has generated itself for that port, its "own" BPDU so to speak. This is the one it sends out every Hello interval.
A blocked port will remain in blocking state as long as inferior BPDUs (compared to the switch generated BPDU) are received for the port. If no BPDUs are received, after MaxAge, the port will transition to listening state.
When a new (different) BPDU is received it depends on the topology. If the port will become now Root Port or Designated Port, the STP topology is changed and the port will transition to listening, learning, forwarding. Otherwise it will remain in blocking state.
After my first publication of the book OSPF Demystified With RFC in 2014 which goes beyond the CCIE level which explores OSPF from the RFC's perspective. Since one year I had the idea : why not write a book for CCIE Enterprise and Infrastructure to be an ...
Do you use Cisco DNA Center? Have you used and are you willing to provide your feedback in using the Cisco DNA Center help and documentation?
If so, we’d like you to complete the survey linked below. Your feedback will help provide more effective and easi...
Listen: https://smarturl.it/CCRS9E18Follow us: https://twitter.com/CiscoChampion Reaching the height of your career is no simple feat. It often requires a combination of pursuing the right education, building the right professional network and being ...