A protocol for transferring data over a network that requires a session connection before data is sent. In TCP/IP this step is accomplished by sending a SYN packet.
With a connectionless protocol, no session connection is required before data is transmitted. UDP and IP are examples of connectionless protocols.
Internet Control Message Protocol (ICMP)
The protocol used to send informational messages and test network connectivity.
The logical component of a connection that identifies the service running on a network device. For example, port 110 is the POP3 mail service.
An attack on a network that requires guessing ISNs. See also initial sequence number (ISN).
The six flags in a TCP header are switches that can be set to on or off to indicate the status of a port or service.
Transmission Control Protocol/Internet Protocol (TCP/IP)
The main protocol used to connect computers over the Internet.