Topology: view the attachment
In the situation of core network CG server double connect to S9300 switch, CG server appear business blocking alarm, S9300 switch interface traffic increase sharply.
Open STP on S9300, enable BPDU packet pass through function, layer 2 circle test function of CG is done, circle is disappeared, access successfully.
bpdu stp bridge role provider
Core network CG server double connect to S9300 switch, CG server 2 network card interface interconnect, because it did not comfirm the CG supporting function clearly, consider that CG server does support any layer 2 circle test protocol in 2 network card interface interconnect situation (practical situation CG defaultly open STP function), so the 2 S9300 switch did not open the BPDU packet pass through function (STP packet sent by CG is passed by S9300 switch when S9300 did not enable STP function); it one network card of CG server send STP packet, interrupting on S9300 switch, and it did not pass to other side of CG server, layer 2 circle test function of CG failed.
Because CG server support STP function defaultly, it can receive, send and modify STP packet, when S9300 did not open the BPDU packet pass through function, it cannot do the layer 2 circle test between S9300 switchs, and it cannot broke the circle, so access failed.
Know the topology: whether the core network device support layer 2 STP function.