Port Numbers

A client packet is received by a server. The packet has a destination port number of 53. What service application is the client requesting?

DNS

A client packet is received by a server. The packet has a destination port number of 22. What service application is the client requesting?

SSH

A client packet is received by a server. The packet has a destination port number of 21. What service application is the client requesting?

FTP

A client packet is received by a server. The packet has a destination port number of 25. What service application is the client requesting?

SMTP

A client packet is received by a server. The packet has a destination port number of 143. What service application is the client requesting?

IMAP

A client packet is received by a server. The packet has a destination port number of 23. What service application is the client requesting?

Telnet