Sentry Policies create mappings between Group Policies for Meraki networking equipment and tags in Systems Manager. This allows for traffic shaping, scheduling, security and VLAN rules to applied to devices based off their tags in Systems Manager. By adding dynamic tags, such as security policies, devices can automatically move between Group Policies based of the posture of the device.
To setup a Sentry Policy, navigate to Network-wide > Configure > Sentry Policies. Select the Systems Manager network in question followed by a scope, the tags for the devices enrolled in SM and finally the Group Policy to apply.