Chapter 3 - Understanding Basic Network Security

Question 1

Connectivity Protocols

Answer 1

TCP
UDP
IP
ICMP
ARP
NDP

Question 2

Encryption Protocols

Answer 2

SSH
SCP
SSL
TLS
IPSec

Question 3

SSH

Answer 3

Acronym : Secure Shell
Function : Used by Secure Copy (SCP) and Securite File Transfer Protocol (SFTP)
Port TCP 22

Question 4

SCP

Answer 4

Acronym : Secure Copy Protocol
Function : Send encrypted files over network
Port : TCP 22

Question 5

SSL

Answer 5

Acronym : Secure Sockets Layer
Function : Secure HTTP as HTTPS with certificates
Used by : HTTPS, SMTP, LDAP, LDAPv2
Port : TCP 443 with HTTPS, TCP 465 with SMTP, TCP 636 with LDAP

Question 6

TLS

Answer 6

Acronym : Transport Layer Security
Function : Designated replacement for SSL
Used by : HTTPS, LDAPv3
Port : TCP 443 with HTTPS, TCP 636 with LDAP

Question 7

IPSec

Answer 7

Acronym : none
Function : Encrypt IP traffic. Works with IPv4 & IPv6. Used in Tunnel mode with VPN connections.
Main components : Authentication Header (AH) + Encapsulation Security Payload (ESP)
Port : Internet Key Exchange (IKE) with UDP 500

Question 8

Application protocols

Answer 8

HTTP
HTTPS
FTP
SFTP
FTPS
TFTP
Telnet
SNMP
NetBIOS
LDAP
Kerberos
Microsoft SQL Server
RDP

Question 9

IPv4 classes

Answer 9

Class A : 0.0.0.0 - 127.255.255.255
Class B : 128.0.0.0 - 191.255.255.255
Class C : 192.0.0.0 - 223.255.255.255

Question 10

IPv6 benefits over IPv4

Answer 10

Significantly larger address space

IPsec built in (everything encrypted)

Question 11

DNS zones

Answer 11

A : host record (IPv4)
AAAA : host record (IPv6)
PTR : pointer record (opposite of A record)
MX : mail exchanger
CNAME : canonical name / alias

Question 12

DNS ports

Answer 12

TCP 53 : zone transfers

UDP 53 : name resolution

Question 13

Ports ranges

Answer 13

0 - 1023 : well-known ports
1024 - 49151 : registered ports
49152 - 65535 : dynamic and private ports

Question 14

IPv4 primary methods to handle traffic

Answer 14

Unicast : one-to-one traffic

Broadcast : one-to-all traffic

Question 15

Firewall rule general format

Answer 15

PPSDP
Permission
Protocol
Source
Destination
Port

Question 16

NAT benefits

Answer 16

Public IP addresses don’t need to be purchased for all clients
NAT hides internal computers from the internet

Question 17

NAT modes

Answer 17

Static NAT

Dynamic NAT

Question 18

OSI model layers

Answer 18

"All people seem to need data processing"
"Please do not throw sausage pizza away"
1. Physical
2. Data Link
3. Network
4. Transport
5. Session
6. Presentation
7. Application

Question 19

Physical layer

Answer 19

Devices : Cables, hubs

Protocols : Ethernet, cabling protocols

Question 20

Data Link layer

Answer 20

Devices : switches

Protocols : MAC, ARP, NDP, VLANs

Question 21

Network layer

Answer 21

Devices : Router, Layer 3 switch

Protocols : IPv4, IPv6, IPsec, ICMP

Question 22

Transport layer

Answer 22

Protocols : TCP, UDP

Question 23

Application

Answer 23

Devices : proxies, application-proxy firewalls, web application firewalls, web security gateways, UTM security appliances