Answer:
TCP RST flag
Explanation:
The RST is the Transmission Control Protocol, TCP Reset package sent back to a source of an unexpected TCP packet by the host, as a response, through the same route connection.
Where one side of the TCP connection has received malformed, unexpected packets such that the TCP connection is yet to recover, the TCP reset package, RST, is sent to the source of the packets to indicate the need for the termination of the connection due to a fatal error
