TCP/IP: A Closer Look

Three Flags are Widely Used
- SYN bit set to 1 in a TCP segment to request a connection
- ACK bit set to 1 in a segment to acknowledge a received TCP segment
- FIN bit set to 1 in a segment to inform of a connection closure

Hdr Len

(4)

Flags (6)

Window Size (16)

Reserved (6)

Three Flags are Widely Used