There are two of port states in STP: Disabled and Blocking,and the a website explain their difference
Disabled : This port is shutdown,and it won't send or receive any frame
Blocking : This port won't send or receive any data frame,but it will still receive BPDU
Now,here is a problem,i thought BPDU is a data frame,when some switches decide who can be the root bridge,they will send this data frame,i mean BPDU,to each others to decide.But now according to the explanation above,it seems that BPDU and data frame are not the same ,because the port won't send or receive any data frame,but it will still receive BPDU when port is blocking.
Can anyone tell me the difference between data frame and BPDU in STP??thanks a lot