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New Member

Switch BPDU issue

Hi all,

Does BPDU is sent from root bridge to access switch. If so, what is the command I can see access switch is receiving BPDU.


Re: Switch BPDU issue

show spanning-tree interface <>



Re: Switch BPDU issue

WS-C4507R#sh spanning-tree interface g3/1 detail

Port 129 (GigabitEthernet3/1) of VLAN0001 is root forwarding

Port path cost 19, Port priority 128, Port Identifier 128.129.

Designated root has priority 32768, address 000e.8389.8d00

Designated bridge has priority 32769, address 0014.f246.e080

Designated port id is 128.39, designated path cost 4

Timers: message age 16, forward delay 0, hold 0

Number of transitions to forwarding state: 1

Link type is point-to-point by default, Peer is STP

BPDU: sent 5, received 6882


here is where you see the in/out BPDU count.

Notice that this is the interface looking to the root bridge and that's why the in count is high and there is barely no sent BPDUs which is normal

New Member

Re: Switch BPDU issue

Hi, Acbenny,

I guess BPDU package is sent NOT only from root bridge, it was sent from all the switches witch connected within the same network. the purpose of the PBDU packege is to exchange STP information, such as BID, MAC, Vlan information and STP mode.

hope this help.