I have been searching for docs about how BPDU packet being marked in the Cisco network , could not find any.
Someone says the BPDU packet has cos value of 6/7 by default in Cisco switches, however I could not find any Cisco document ever mentione this default value.
Also, only 802.1Q packet carry cos value. If there is no trunking at all in the network. Where this QoS value being carried in the BPDU packet ?.... ( by going through the BPDU packet formate, I also do not see any field could carry QoS marking value. ). In such network environment, how can we make sure this BPDU packet being transimitted with high priority ?
This is something I really would like to understand more.
Any help will be very appreciated.
Angela