BPDU Guard Not working and loops happen

[ali ezzat1]

Dears,

user takes a network cable and plugs it into two wall jacks,  this creates a loop, a broadcast storm will likely follow. This happened to us by having an end user hooking up their IP phone to two network jacks. It brought down the entire network.

and

- BPDU GUARD enabled globally 

- BPDU filter not enabled

- port fast enabled under access ports

switch C3750 connected to core c9500

logs 

STP-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV

Thanks to share the solution for this issue

[marce1000]

 - Please don't make dups :

          https://community.cisco.com/t5/switching/bpdu-guard-not-working-and-loops-happened/m-p/4139725

 M.