A packet processing method and apparatus, and a related device, the method including generating, by a first device, a flow filtering rule, where the flow filtering rule includes a match item and an action item, and where the match item comprises an Internet Protocol (IP) address and an autonomous domain identifier, and sending, by the first device, the flow filtering rule to a second device, where the action item is used to instruct the second device to process, based on a packet processing mode indicated by the action item, a packet matching the match item.