About RA guard
RA guard allows Layer 2 access devices to analyze and block unwanted and forged RA messages.
Upon receiving an RA message, the device makes the forwarding or dropping decision based on the role of the attached device or the RA guard policy.
If the role of the device attached to the port is router, the device forwards all RA messages received on the port. If the role is host, the device directly drops all RA messages received on the port.
If no role is set for the port, the device uses the RA guard policy to match the information found in the RA message.
If the RA message content matches every criterion in the policy, the device forwards the message.
If the RA message content is not validated, the device drops the message.