Amazon VPC
Logically isolated virtual network.
<h3>Amazon VPC (Virtual Private Cloud)</h3>
<p><strong>Definition:</strong> Isolated virtual network in AWS.</p>
<p><strong>Components:</strong></p>
<ul>
<li><strong>Subnets:</strong> Public/Private segments of IP range.</li>
<li><strong>Route Tables:</strong> Control traffic routing.</li>
<li><strong>Internet Gateway:</strong> Connects VPC to internet.</li>
<li><strong>NAT Gateway:</strong> Internet across for private subnets.</li>
<li><strong>VPC Peering:</strong> Connect two VPCs.</li>
<li><strong>Endpoints:</strong> Private connection to AWS services.</li>
<li><strong>Flow Logs:</strong> Capture IP traffic.</li>
</ul>
Internet Gateway
Connects VPC to the internet.
<h3>Internet Gateway</h3>
<p><strong>Definition:</strong> Horizontally scaled, redundant VPC component for internet connectivity.</p>
NAT Gateway
Internet across for private subnets.
<h3>NAT Gateway</h3>
<p><strong>Definition:</strong> Network Address Translation for private subnets to access internet.</p>
<p><strong>Types:</strong> Public (in public subnet), Private (for cross-VPC routing).</p>
VPC Peering
Connect two VPCs.
<h3>VPC Peering</h3>
<p><strong>Definition:</strong> Connect two VPCs using private IP addresses.</p>
<p><strong>Limitations:</strong> No transitive peering, overlapping CIDRs not allowed.</p>
Security Groups
Virtual firewall for EC2 instances.
<h3>Security Groups</h3>
<p><strong>Definition:</strong> Stateful virtual firewall for EC2 instances.</p>
<ul>
<li>Allow rules only.</li>
<li>Reference other security groups.</li>
<li>Applied at instance level.</li>
</ul>
AWS Transit Gateway
Connect VPCs and on-premises networks.
<h3>AWS Transit Gateway</h3>
<p><strong>Definition:</strong> Network transit hub connecting VPCs and on-premises networks.</p>
<p><strong>Features:</strong> Hub-and-spoke architecture, cross-region peering, route tables.</p>
AWS Site-to-Site VPN
Secure connection to on-premises.
<h3>AWS Site-to-Site VPN</h3>
<p><strong>Definition:</strong> IPSec VPN connection between VPC and on-premises network.</p>
<p><strong>Components:</strong> Virtual Private Gateway, Customer Gateway, VPN Connection.</p>
AWS Direct Connect
Dedicated network connection to AWS.
<h3>AWS Direct Connect</h3>
<p><strong>Definition:</strong> Dedicated network connection from on-premises to AWS.</p>
<p><strong>Types:</strong> Dedicated (1/10/100 Gbps), Hosted (50Mbps-10Gbps).</p>
Amazon Route 53
Scalable Domain Name System (DNS).
<h3>Amazon Route 53</h3>
<p><strong>Definition:</strong> Scalable DNS and domain registration.</p>
<p><strong>Routing Policies:</strong> Simple, Weighted, Latency-based, Failover, Geolocation, Geoproximity, Multivalue Answer.</p>
<p><strong>Features:</strong> Health Checks.</p>
Amazon CloudFront
Fast Content Delivery Network (CDN).
<h3>Amazon CloudFront</h3>
<p><strong>Definition:</strong> Global Content Delivery Network (CDN).</p>
<p><strong>Features:</strong></p>
<ul>
<li>Edge Locations (300+ globally).</li>
<li>Origin Shield (secondary cache).</li>
<li>Field-Level Encryption.</li>
<li>Lambda@Edge (run code at edge).</li>
</ul>
<p><strong>Use Cases:</strong> Static/dynamic content delivery, video streaming, security.</p>
