Câu 56: 648-385: Cisco Express Foundation for Field Engineers

Refer to the exhibit. Switches A and C are running PVST+ STP, and switch B is running 802.1Q STP, if the BPDU of the root in VLAN 1 is better than the BPDU of the root in VLAN 2, then there is no blocking port in the VLAN 2 topology. The BPDU of VLAN 2 never makes a full circle around the topology, it is replaced by the VLAN 1 BPDU on the B_C link, because B runs only one STP merged with VLAN ! STP of PVST+ Thus, there is a forwarding loop What does PVST+ do to correct this?

1. A. Switch A sends PVST+BPDUs of VLAN 2 (to the SSTP address that is flooded by switch B) towards Switch C. Switch C will put port C-B into a type- inconsistent,which prevents the loop — đáp án hiện tại
2. B. Switch B sends PVST+BPDUs of VLAN 1 (to the SSTP address that is flooded by switch A) towards Switch C. Switch C will put port C-B into a type- inconsistent,which prevents the loop
3. C. Switch C sends PVST+BPDUs of VLAN 2 (to the SSTP address that is flooded by switch B) towards Switch C. Switch C will put port C-B into a type- inconsistent,which prevents the loop
4. D. Switch A sends PVST+BPDUs of VLAN 1 (to the SSTP address that is flooded by switch B) towards Switch B. Switch A will put port C-B into a type-