How to avoid cookies?

In order to initiate a TCP connection, the client sends a TCP SYN packet to the server. In response, the server sends a TCP SYN+ACK packet back to the client. One of the values in this packet is a sequence number, which is used by the TCP protocol to reassemble the data stream. According to the TCP specification, that first sequence number sent by an endpoint can be any value as decided by that endpoint. While many implementations use zero as the initial sequence number, SYN Cookies are initial sequence numbers that are carefully constructed according to the following rules: