The Link Management Protocol (LMP) is activated on each link of the StackWise Virtual link as soon as it is brought up online. The LMP performs the following functions: - Verifies link integrity by establishing bidirectional traffic forwarding, and rejects any unidirectional links - Exchanges periodic hellos to monitor and maintain the health of the links - Negotiates the version of StackWise Virtual header between the switches StackWise Virtual link role resolution https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9000/nb-06-cat-9k-stack-wp- cte-en.html