This read-only MacAddress object reports the source MAC address recorded in a SAVI filtering table entry, keyed by IP address type, interface, and source IP. Admins use it to see which MAC address is associated with a source IP that SAVI has filtered or is tracking, useful when auditing why a particular host's traffic is being allowed or blocked. For example, an admin investigating a filtering entry tied to a suspicious IP would check this field to identify the actual hardware MAC address behind that IP on the port.