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AWS Solutions Architect - Associate

Networking - VPC

CIDR - Classless Inter-Domain Routing

Private vs Public IP Addresses (IPv4)

Default VPC

VPC - Virtual Private Cloud

VPC Subnets

IGW - Internet Gateways

NAT Instances - Network Address Translation (outdated)

NAT Gateway

Comparison between NAT Instance and NAT Gateway

DNS Resolution in VPC

-DNS Resolutions settings: - enableDnsSupport: - By default is set to true - Helps decide if DNS resolution is supported for the VPC - If true, queries the AWS DNS server at - enableDNSHostName: - By default is set to false for an user created VPC, true for the Default VPC - Won’t do anything unless enableDnsSupport=true - If true, the VPC assigns public host names to EC2 instances

Network Access Control Lists (NACL) and Security Groups (SG)

Security Group Network ACL
Operates at the instance level Operates at the subnet level
Supports allow rules only Supports allow rules and deny rules
It is stateful: return traffic is automatically allowed It is stateless: return traffic must be explicitly allowed by the rules
All rules are evaluated before deciding to allow traffic Rules have a precedence when deciding whether to allow or deny traffic
It is associated to an instance inside of a VPC Automatically applies to all instances in the subnet

VPC Peering

VPC Endpoints

VPC FLow Logs

Flow Log Syntax

<version> <account-id> <interface-id> <srcaddr> <dstaddr> <srcport> <dstport> <protocol> <packets> <bytes> <start> <end> <action> <log-status>

Bastion Hosts

Site to Site VPN

Direct Connect (DX)

Direct Connect Encryption

Egress Only Internet Gateway

Exposing Services in a VPC to Other VPC

AWS VPN CloudHub

Transit Gateway

VPC Summary