-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > A port is in either of the two states ie , open or closed at > any point of time. >
That is not exactly correct. Ports are not either open or closed. Depending on the protocol, there are actually several different states of activity. For instance, in TCP - state is managed as an element of the Transmission Control Block (TCB). The various TCP states are: LISTEN, SYN-SENT, SYN-RECEIVED, ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT, and the fictional state CLOSED. CLOSED is fictional because it represents the state when there is no TCB, and therefore, no connection. Thank you for your time and attention, ======================== Brad Bemis Information Security Services Airborne Express (206) 830-3478 ======================== Email Notice: This communication may contain sensitive information. If you are not the intended recipient, or believe that you have received this communication in error; do not print, copy, retransmit, disseminate, or otherwise use the information contained herein for any purpose. Please alert the sender that you have received this message in error, and delete the copy that you received. -----BEGIN PGP SIGNATURE----- iQA/AwUBPyaZGpDnOfS48mrdEQJiWgCaAk28bAb21CBQ7SiQT9lJ+ZcjBOQAoJ89 DG/70ZiEnqFJ8pI0D6v4yslW =E5DZ -----END PGP SIGNATURE----- --------------------------------------------------------------------------- ----------------------------------------------------------------------------