106021: Deny protocol reverse path check
Cisco ASA is a security device that provides the combined capabilities of a firewall, an antivirus, and an intrusion prevention system. It also facilitates virtual private network (VPN) connections. It helps to detect threats and stop attacks before they spread through the network.
Message: %ASA-1-106021: Deny protocol reverse path check from source_address to dest_address on interface interface_name.
Event 106021 is generated when a packet that does not have a source address represented by a route is discarded by unicast RPF, which would have been enabled with 'IP verify reverse-path' command.
How could you resolve this situation?
If the unicast RPF feature has been enabled, no user action is required. The ASA would repel the attack.