yeah exactly but the ROOT SWITCH only acknowledges the last hop down stream switch from which it received the TCN BPDU, and TC FLAG is also set with TCN FLAG…but after that it only set the TC FLAG for 35 secs in its CONFIGURATION BPDU…which is then propagated to all the down stream switches…
FLOW BPDU TYPE FLAGS
———————–> TCN nil nil
<———————– CONFIG BPDU 1 0
————————> TCN nil nil
<———————— CONFIG BPDU 1 1
<———————— CONFIG BPDU 0 1
and continues for 35 secs for all dwn stream switches
??????????????????????????????? http://goo.gl/BPDU???***?????????????????????????????????????
Interesting, I was thinking too general: Sticky MACs, BPDU Guard and ACLs.
Cisco CCNP / BCMSN Exam Tutorial: BPDU Skew Detection And Cisco Switches: Learn how and why? http://goo.gl/fb/WVb6V
Re: Invalid BPDU transmission? http://dlvr.it/75NtH
Re: Invalid BPDU transmission? http://dlvr.it/75Nt7
Re: Invalid BPDU transmission? http://dlvr.it/75M7P
Re: Invalid BPDU transmission? http://dlvr.it/75LRd
Invalid BPDU transmission? http://dlvr.it/75LRS
?????????????????????????????? http://goo.gl/BPDU
?BPDU????????????????????????????????????????????????????????????????????????L2??????????????????????????????????