TCP Flags

Transmission Control Protocol (TCP) Flags are control bits for TCP messages. These flags indicate how packets should be handled or indicate connection states.

Flag	Description
SYN	Synchronize sequence numbers.
ACK	Acknowledgment field is significant.
FIN	No more data from sender.
RST	Reset the connection.
URG	Urgent pointer field is significant.
PSH	Push function.
CWR	Congestion Window Reduced.
ECE	TCP peer is ECN capable.