Cisco switches are now running PVST+,and H3C running MSTP, how can they talk to each other, without changing any configuration on Cisco site. I know that vlan 1 can prevent loop because the BPDU of VLAN1 is standard.But I don't know other vlans(for example vlan 2,3) if can communicate with each other and prevent loop? Cisco will consider H3C as hub,and H3C just forward the pvst+ BPDU to another cisco switch but not to deal with it?