Change NodeBalancer health check port
You can change your NodeBalancer's health check port through your Linode Manager. The information below will cover changing a port, as well as, adding additional ports, depending on what you prefer.
To change the health check port, go to the edit configuration options for that specific Node Balancer. The first option in the configuration settings should allow you change the Port you would prefer Health Check to listen to.
If you prefer to add additional ports, you would need additional configurations added per each port you would like Health Check to listen to. This can be done on your Node Balancer page.
Once there, select 'Create Configuration' within your 'Configuration' options. Change Port to preferred choice and adjust any setting configurations that may be needed. This feature will allow you to add and configure any additional ports within your Node Balancer.
Additional details on passive and active health checks can be found here