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.