Ports

Question 1

20 and 21

Answer 1

FTP (TCP) (20 is for data, 21 is for connection/command/control)

Question 2

22 (TCP)

Answer 2

SSH, SCP, & SFTP (all of these are secured and encrypted)

Question 3

23

Answer 3

Telnet

Question 4

25

Answer 4

SMTP (TCP) - Outgoing email

Question 5

49

Answer 5

TACACS/TACACS+ (TCP or UPD)

Question 6

53

Answer 6

DNS (UDP for queries, TCP for zone-transfers)

Question 7

69

Answer 7

TFTP (UDP)

Question 8

80

Answer 8

HTTP (TCP)

Question 9

88

Answer 9

Kerberos

Question 10

110

Answer 10

POP3 (TCP) - Incoming email. Port 995 is POP3 over SSL (encrypted)

Question 11

123

Answer 11

NTP (Network Time Protocol. NTP-UDP-123)

Question 12

143

Answer 12

IMAP (TCP) - also for incoming email

Question 13

161

Answer 13

SNMP (version 3 is the most secure so only use this version)

Question 14

389

Answer 14

LDAP (non-secure)

Question 15

443

Answer 15

SSL and HTTPS (TCP) (SSL used for a secure connection via a web browser)

Question 16

636

Answer 16

Secure LDAP, secured with SSL or TLS

Question 17

995

Answer 17

POP3 over SSL (encrypted e-mail retreival)

Question 18

1433

Answer 18

MS-SQL Database

Question 19

1812 and 1813

Answer 19

RADIUS (UDP 1812 for authentication, UDP 1813 for accounting)

Question 20

3389

Answer 20

RDP (TCP) Remote Desktop

Question 21

6667

Answer 21

IRC (Internet Relay Chat)