GCGA Ch. 3 Reviewing Basic Networking Concepts (ST)

Question 1

OSI Model

Answer 1

OSI Model ->

Please Do Not Throw Sausage Pizza Away

Physical Data Link Network Transport Session Presentation Application

Question 2

TCP & UDP

Answer 2

The Transmission Control Protocol (TCP) is a connection oriented protocol that provides guaranteed delivery while the User Datagram Protocol (UDP) is a connectionless protocol that provides “best effort” delivery.

Question 3

FTP, SFTP, & FTPS

Answer 3

File Transfer Protocol - used to send files over networks; SSH (port 22) encrypts Secure Copy (SCP) and Secure FTP (SFTP). TLS encrypts FTPS. FTP uses TCP 21 (control connections) and TCP 20 (data connections); FTPS uses TCP 21 (control connection in explicit mode), TCP 990 (control connection in implicit mode).

Question 4

SMTP & SMTPS

Answer 4

Simple Mail Transfer Protocol/Secure - uses TCP port 25 (original) and 587 (encrypted over TLS)

Question 5

HTTP & HTTPS

Answer 5

HyperText Transmission Protocol/Secure. HTTP is unencrypted and on port 80. HTTPS encrypts browser-based traffic with TLS using TCP port 443.

Question 6

LDAP & LDAPS

Answer 6

Lightweight Directory Access Protocol/LDAP Secure - LDAP runs over TCP port 389; LDAPS runs over TCP port 636

Question 7

SSH & RDP

Answer 7

Secure SHell. Administrators commonly connect to remote systems using SSH (on port 22) instead of Telnet because SSH encrypts the connection. Administrators also use Remote Desktop Protocol (RDP) to connect to remote systems graphically using TCP port 3389.

Question 8

NTP

Answer 8

Network Time Protocol - provides time synchronization services (UDP 123)

Question 9

DNS

Answer 9

Domain Name System - provides domain name resolution; includes A records for IPv4 addresses and AAAA records for IPv6. MX -> mail servers, MX w/ lowest preference is primary mail server; DNS uses TCP 53 -> zone transfers & UDP 53 -> client queries

Question 10

DNSSEC

Answer 10

Domain Name System Security Extensions - provides validation for DNS responses by adding a Resource Record Signature (RRSIG)

Question 11

RRSIG

Answer 11

Resource Record Signature - provides data integrity & authentication; helps prevent DNS poisoning attacks