Peer switch allows the sahring of the same BPDU. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6- x/interfaces/configuration/guide/b_Cisco_Nexus_9000_Series_NX- OS_Interfaces_Configuration_Guide/b_Cisco_Nexus_9000_Series_NX- OS_Interfaces_Configuration_Guide_chapter_0111.html