Question

Consider the following statements:
$S_1$: IMAP protocol always synchronized with the mail server but not POP protocol.
$S_2$ : POP protocol is used to download an e-mail form mail-box server to a mail client.
$S_3$: DNS uses TCP for its query and response messages.
$S_4$: Firewall works on application but not on network layer.

The number of correct statement are_____

Answer 1

• Statement $S_1$ is correct because IMAP protocol whenever user changes anything on the client side same time it changes on the server side because of sychronized.
• Statement $S_2$ is correct
• DNS uses UDP, so statement $S_3$ is incorrect
• Firewalls works on network layer also called as-packet filters or on application layer, So statement $S_4$ is incorrect.