Networking

Question 1

What is the total amount of ports ?

Answer 1

65 535

Question 2

How does a computer it’s receiving data in form of email or website or other data types?

Answer 2

They carry an identification, a port number

Question 3

explain portnumber 25

Answer 3

SMTP (Simple Mail Transfer Protocol)
- sends outgoing mail to a server
- TCP

Question 4

explain portnumber 110

Answer 4

POP3 (Post Office Protocol)
- downloads incoming mail, mail isn’t saved on server
- TCP

Question 5

explain portnumber 134

Answer 5

IMAP (Internet Message Access Protocol)
- synchronizes incoming mail from a server
- TCP

Question 6

explain portnumber 20, 21

Answer 6

FTP (File Transfer Protocol)
- share files with users in LAN or WAN
- supports authentication, authorization, directory browsing
- unencrypted
TCP

Question 7

explain portnumber 69

Answer 7

TFTP (Trivial FTP)
- push or pull files from a server
- commonly used to manage devices like IP phones, routers, switches
- does NOT support auth, …
- unencrypted
- UDP

Question 8

explain portnumber 22 (extension)

Answer 8

SFTP (Secure FTP)
= Secure implementation of FTP
- supports all the same functions, but encrypted
- extension of SSH, hance they use the same port number
- TCP

Question 9

explain portnumber 23

Answer 9

Telnet
- provides remote command line access to interact with a server
- considered insecure, should no longer be used, use SSH
- TCP

Question 10

explain portnumber 22

Answer 10

SSH (secure shell)
- same as Telnet
- provides encrypted remote command line access to interact with a server
- SSH version 2 added SFTP and SCP support
- TCP

Question 11

explain portnumber 53

Answer 11

DNS (Domain Name Systems)
- resolves domain name to IP addresses
- TCP/UDP

Question 12

explain portnumber 67, 68

Answer 12

DHCP (Dynamic Host Configuration Protocol)
- provides various configurations to client in an IP network via broadcast
- UDP
67 = server port
68 = client port

Question 13

explain portnumber 80, 443

Answer 13

HTTP
- transmits webpages
HTTPS
- encrypted, using SSL and TLS

• TCP

Question 14

explain portnumber 137/139

Answer 14

NetBios (Network Basic Input/Output System)
- provides various network communication features in a windows network
- used in windows before IP networking
- NetBios over TCP/IP is still used in windows
- TCP/UDP

Question 15

explain portnumber 161/162

Answer 15

SNMP (Simple Network Management Protocol)
- used to query, configure, monitor host in LAN
-SNMPv3 encrypts communication, previous versions did not
- UDP

Question 16

explain portnumber 389

Answer 16

LDAP (Lightweight Directory Access Protocol)
- used in domain-based network environments to facilitate system and user management
- TCP/UDP

Question 17

explain portnumber 445

Answer 17

SMB (Server Message Block)
- provides file sharing, network browsing, printing services
- commonly used in windows networks but supported in Linux, macOS, many others
- CIFS (common Internet File System) = open implementation of SMB used on Linux and macOS
- TCP

Question 18

explain portnumber 3389

Answer 18

RDP (Remote Desktop Protocol)
- used to securely remotely access a windows desktop
- TCP