去年,天启和紫月剑一战,一方面紫月剑实力欠缺一点,另一方面《天河魔剑录》烂尾,这一战根本没有尽兴。 The principle is that syn messages are first responded to syn_ack by DDOS protection system. With a specific sequence number (recorded as a cookie). The real client returns an ack and the Acknowledge number is cookie+1. The fake client will not respond. In this way, we can know that the clients corresponding to those IP are real and add the real client IP to the white list. The next access passes directly, while other forged syn messages are intercepted. The following is a schematic diagram of protection:?