AWS Cloud Cert Guide
AWS Cloud
OSI Model
Layers Overview
| Layer | Name | Function | Example Protocols |
|---|---|---|---|
| 7 | Application | User interaction | HTTP, FTP, SMTP |
| 6 | Presentation | Encryption & formatting | SSL/TLS, JPEG |
| 5 | Session | Connection management | NetBIOS, RPC |
| 4 | Transport | Reliable delivery | TCP, UDP |
| 3 | Network | Routing & IP addressing | IP, ICMP |
| 2 | Data Link | MAC addressing | Ethernet, PPP |
| 1 | Physical | Data transmission | Fiber, Ethernet cable |
AWS Networking
I’ve been lucky. While working at OJCommerce, the IT Infrastructure guy made me realize… it’s just networking and he teaches basics Networking 
Zone & Region
1 Region = Multiple AZ
VPC & Subnet
CIDR
$\text{Classless Inter Domain Routing} = \text{base address} + \text{ prefix}$
| IPv4 | IPv6 |
|---|---|
| Identity of the each host in the network | Identity of the each host in the network |
| e.g) 192.168.56.212 | e.g) 11000000.10101000.0111000.11010100 |
● AWS VPC CIDR (IPv4)
- ○ VPC prefix between /16 (65536 IPs) and /28 (16 IPs)
- ○ RFC 1918 IP ranges for Private network and corresponding AWS recommended ranges
- ■ 10.0.0.0/8 => 10.0.0.0 – 10.255.255.255
- ■ 172.16.0.0/12 => 172.16.0.0 - 172.31.255.255
- ■ 192.168.0.0/16 => 192.168.0.0 - 192.168.255.255
- ○ Subnet CIDR prefix between /16 to /28 (same as VPC CIDR)
● AWS VPC CIDR (IPv6)
- ○ VPC CIDR with prefix /56 (2^72 IPs)
- ○ IPv6 CIDR is allocated by AWS
- ○ Subnet CIDR prefix /64
- ○ IPv6 IP addresses are globally unique and publicly routable
Route Tables
Internet Gateway
Security Groups
Network ACL
