AWS Networking & Content Delivery Services Cheat Sheet

Virtual Private Cloud – VPC

• helps define a logically isolated dedicated virtual network within the AWS
• provides control of IP addressing using CIDR block from a minimum of /28 to a maximum of /16 block size
• supports IPv4 and IPv6 addressing
• cannot be extended once created
• can be extended by associating secondary IPv4 CIDR blocks to VPC
• Components
  • Internet gateway (IGW) provides access to the Internet
  • Virtual gateway (VGW) provides access to the on-premises data center through VPN and Direct Connect connections
  • VPC can have only one IGW and VGW
  • Route tables determine network traffic routing from the subnet
  • Ability to create a subnet with VPC CIDR block
  • A Network Address Translation (NAT) server provides outbound Internet access for EC2 instances in private subnets
  • Elastic IP addresses are static, persistent public IP addresses
  • Instances launched in the VPC will have a Private IP address and can have a Public or an Elastic IP address associated with it
  • Security Groups and NACLs help define security
  • Flow logs – Capture information about the IP traffic going to and from network interfaces in your VPC
• Tenancy option for instances
  • shared, by default, allows instances to be launched on shared tenancy
  • dedicated allows instances to be launched on a dedicated hardware
• Route Tables
  • defines rules, termed as routes, which determine where network traffic from the subnet would be routed
  • Each VPC has a Main Route table and can have multiple custom route tables created
  • Every route table contains a local route that enables communication within a VPC which cannot be modified or deleted
  • Route priority is decided by matching the most specific route in the route table that matches the traffic
• Subnets
  • map to AZs and do not span across AZs
  • have a CIDR range that is a portion of the whole VPC.
  • CIDR ranges cannot overlap between subnets within the VPC.
  • AWS reserves 5 IP addresses in each subnet – first 4 and last one
  • Each subnet is associated with a route table which define its behavior
    • Public subnets – inbound/outbound Internet connectivity via IGW
    • Private subnets – outbound Internet connectivity via an NAT or VGW
    • Protected subnets – no outbound connectivity and used for regulated workloads
• Elastic Network Interface (ENI)
  • a default ENI, eth0, is attached to an instance which cannot be detached with one or more secondary detachable ENIs (eth1-ethn)
  • has primary private, one or more secondary private, public, Elastic IP address, security groups, MAC address and source/destination check flag attributes associated
  • AN ENI in one subnet can be attached to an instance in the same or another subnet, in the same AZ and the same VPC
  • Security group membership of an ENI can be changed
  • with pre-allocated Mac Address can be used for applications with special licensing requirements
• Security Groups vs NACLs – Network Access Control Lists
  • Stateful vs Stateless
  • At instance level vs At subnet level
  • Only allows Allow rule vs Allows both Allow and Deny rules
  • Evaluated as a Whole vs Evaluated in defined Order
• Elastic IP
  • is a static IP address designed for dynamic cloud computing.
  • is associated with an AWS account, and not a particular instance
  • can be remapped from one instance to another instance
  • is charged for non-usage, if not linked for any instance or instance associated is in a stopped state
• NAT
  
  • allows internet access to instances in the private subnets.
  • performs the function of both address translation and port address translation (PAT)
  • needs source/destination check flag to be disabled as it is not the actual destination of the traffic for NAT Instance.
  • NAT gateway is an AWS managed NAT service that provides better availability, higher bandwidth, and requires less administrative effort
  • are not supported for IPv6 traffic
  • NAT Gateway supports private NAT with fixed private IPs.
  • Regional NAT Gateway (announced Nov 2025) automatically expands across Availability Zones based on workload footprint, providing simplified setup, enhanced security, and automatic high availability without manual multi-AZ configuration.
• Egress-Only Internet Gateways
  • outbound communication over IPv6 from instances in the VPC to the Internet, and prevents the Internet from initiating an IPv6 connection with your instances
  • supports IPv6 traffic only
• Shared VPCs
  • allows multiple AWS accounts to create their application resources, such as EC2 instances, RDS databases, Redshift clusters, and AWS Lambda functions, into shared, centrally-managed VPCs
• VPC Encryption Controls (announced Nov 2025)
  • allows enforcing encryption in transit for network traffic within the VPC
  • provides centralized encryption policy enforcement and monitoring capabilities
  • supports monitor and enforce modes to audit and enforce encryption compliance
  • transitioned to paid feature starting March 2026

VPC Peering

• allows routing of traffic between the peer VPCs using private IP addresses with no IGW or VGW required.
• No single point of failure and bandwidth bottlenecks
• supports inter-region VPC peering
• Limitations
  • IP space or CIDR blocks cannot overlap
  • cannot be transitive
  • supports a one-to-one relationship between two VPCs and has to be explicitly peered.
  • does not support edge-to-edge routing.
  • supports only one connection between any two VPCs
• Private DNS values cannot be resolved
• Security groups from peered VPC can now be referred to, however, the VPC should be in the same region.

VPC Endpoints

• enables private connectivity from VPC to supported AWS services and VPC endpoint services powered by PrivateLink
• does not require a public IP address, access over the Internet, NAT device, a VPN connection, or Direct Connect
• traffic between VPC & AWS service does not leave the Amazon network
• are virtual devices.
• are horizontally scaled, redundant, and highly available VPC components that allow communication between instances in the VPC and services without imposing availability risks or bandwidth constraints on the network traffic.
• Gateway Endpoints
  • is a gateway that is a target for a specified route in the route table, used for traffic destined to a supported AWS service.
  • only S3 and DynamoDB are currently supported
• Interface Endpoints OR Private Links
  
  • is an elastic network interface with a private IP address that serves as an entry point for traffic destined to a supported service
  • supports services include AWS services, services hosted by other AWS customers and partners in their own VPCs (referred to as endpoint services), and supported AWS Marketplace partner services.
  • Private Links
    • provide fine-grained access control
    • provides a point-to-point integration.
    • supports overlapping CIDR blocks.
    • supports transitive routing
  • Access to VPC Resources over PrivateLink (announced Dec 2024) – allows sharing any VPC resource using AWS RAM and accessing them privately using VPC endpoints, without requiring the resource to sit behind a NLB.

CloudFront

• provides low latency and high data transfer speeds for the distribution of static, dynamic web, or streaming content to web users.
• delivers the content through a worldwide network of data centers called Edge Locations or Point of Presence (PoPs)
• keeps persistent connections with the origin servers so that the files can be fetched from the origin servers as quickly as possible.
• dramatically reduces the number of network hops that users’ requests must pass through
• supports multiple origin server options, like AWS hosted service for e.g. S3, EC2, ELB, or an on-premise server, which stores the original, definitive version of the objects
• single distribution can have multiple origins and Path pattern in a cache behavior determines which requests are routed to the origin
• Web distribution supports static, dynamic web content, on-demand using progressive download & HLS, and live streaming video content
• RTMP distributions were deprecated and removed on December 31, 2020. Use Web distributions with HTTP-based streaming protocols (HLS, DASH) instead.
• supports HTTPS using either
  • dedicated IP address, which is expensive as a dedicated IP address is assigned to each CloudFront edge location
  • Server Name Indication (SNI), which is free but supported by modern browsers only with the domain name available in the request header
• For E2E HTTPS connection,
  • Viewers -> CloudFront needs either a certificate issued by CA or ACM
  • CloudFront -> Origin needs a certificate issued by ACM for ELB and by CA for other origins
• Security
  • Origin Access Control (OAC) is the recommended method to restrict content from S3 origin to be accessible from CloudFront only. OAC supports SSE-KMS, all HTTP methods, and all AWS Regions.
    • Origin Access Identity (OAI) is the legacy method. OAI creation was deprecated in 2024 and new distributions (as of March 2026) can only use OAC. Existing OAI configurations continue to work but migration to OAC is recommended.
  • supports Geo restriction (Geo-Blocking) to whitelist or blacklist countries that can access the content
  • Signed URLs
    
    • to restrict access to individual files, for e.g., an installation download for your application.
    • users using a client, for e.g. a custom HTTP client, that doesn’t support cookies
  • Signed Cookies
    • provide access to multiple restricted files, for e.g., video part files in HLS format or all of the files in the subscribers’ area of a website.
    • don’t want to change the current URLs
  • integrates with AWS WAF, a web application firewall that helps protect web applications from attacks by allowing rules configured based on IP addresses, HTTP headers, and custom URI strings
• supports GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE to get object & object headers, add, update, and delete objects
  • only caches responses to GET and HEAD requests and, optionally, OPTIONS requests
  • does not cache responses to PUT, POST, PATCH, DELETE request methods and these requests are proxied back to the origin
• object removal from the cache
  • would be removed upon expiry (TTL) from the cache, by default 24 hrs
  • can be invalidated explicitly, but has a cost associated, however, might continue to see the old version until it expires from those caches
  • objects can be invalidated only for Web distribution
  • use versioning or change object name, to serve a different version
  • Tag-based cache invalidation (announced May 2026) – allows tagging cached objects via origin response headers or S3 metadata and invalidating them by tag directly through the CloudFront API.
• supports adding or modifying custom headers before the request is sent to origin which can be used to
  • validate if a user is accessing the content from CDN
  • identifying CDN from which the request was forwarded, in case of multiple CloudFront distributions
  • for viewers not supporting CORS to return the Access-Control-Allow-Origin header for every request
• supports Partial GET requests using range header to download objects in smaller units improving the efficiency of partial downloads and recovery from partially failed transfers
• supports compression to compress and serve compressed files when viewer requests include Accept-Encoding: gzip in the request header
• supports different price classes to include all regions, or only the least expensive regions and other regions without the most expensive regions
• supports access logs which contain detailed information about every user request for both web distribution
• Edge Compute
  • CloudFront Functions – lightweight JavaScript functions for simple request/response transformations (URL rewrites, header manipulation, redirects) executed at viewer request/response events with sub-millisecond latency
  • Lambda@Edge – more powerful compute for complex processing at origin request/response and viewer request/response events
  • CloudFront KeyValueStore (launched 2023) – a globally distributed, low-latency data store that CloudFront Functions can read at runtime for dynamic routing, A/B testing, feature flags, and geo-routing without redeploying function code
• CloudFront Flat-Rate Pricing Plans – combine CDN, AWS WAF, DDoS protection, bot management, Route 53 DNS, CloudWatch Logs ingestion, serverless edge compute, and S3 storage credits into a single monthly price

AWS VPN

• AWS Site-to-Site VPN provides secure IPSec connections from on-premise computers or services to AWS over the Internet
• is cheap, and quick to set up however it depends on the Internet speed
• delivers high availability by using two tunnels across multiple Availability Zones within the AWS global network
• VPN requires a Virtual Gateway – VGW and Customer Gateway – CGW for communication
• VPN connection is terminated on VGW on AWS
• Only one VGW can be attached to a VPC at a time
• VGW supports both static and dynamic routing using Border Gateway Protocol (BGP)
• VGW supports AWS-256 and SHA-2 for data encryption and integrity
• AWS Client VPN is a managed client-based VPN service that enables secure access to AWS resources and resources in the on-premises network.
• AWS VPN does not allow accessing the Internet through IGW or NAT Gateway, peered VPC resources, or VPC Gateway Endpoints from on-premises.
• AWS VPN allows access accessing the Internet through NAT Instance and VPC Interface Endpoints from on-premises.

Direct Connect

• is a network service that uses a private dedicated network connection to connect to AWS services.
• helps reduce costs (long term), increases bandwidth, and provides a more consistent network experience than internet-based connections.
• supports Dedicated and Hosted connections
  • Dedicated connection is made through a 1 Gbps, 10 Gbps, or 100 Gbps Ethernet port dedicated to a single customer.
  • Hosted connections are sourced from an AWS Direct Connect Partner that has a network link between themselves and AWS.
• provides Virtual Interfaces
  • Private VIF to access instances within a VPC via VGW
  • Public VIF to access non VPC services
  • Transit VIF to access one or more Amazon VPC Transit Gateways associated with Direct Connect gateways, enabling connectivity to multiple VPCs through a single VIF
• requires time to setup probably months, and should not be considered as an option if the turnaround time is less
• does not provide redundancy, use either second direct connection or IPSec VPN connection
• Virtual Private Gateway is on the AWS side and Customer Gateway is on the Customer side
• route propagation is enabled on VGW and not on CGW
• A link aggregation group (LAG) is a logical interface that uses the link aggregation control protocol (LACP) to aggregate multiple dedicated connections at a single AWS Direct Connect endpoint and treat them as a single, managed connection
• VIF Rate Limiters (announced June 2026) on dedicated connections help prevent network congestion caused by unexpected traffic spikes on a VIF that could consume all available bandwidth impacting other VIFs on the same connection.
• Direct Connect vs VPN IPSec
  • Expensive to Setup and Takes time vs Cheap & Immediate
  • Dedicated private connections vs Internet
  • Reduced data transfer rate vs Internet data transfer cost
  • Consistent performance vs Internet inherent variability
  • Do not provide Redundancy vs Provides Redundancy

Route 53

• provides highly available and scalable DNS, Domain Registration Service, and health-checking web services
• Reliable and cost-effective way to route end users to Internet applications
• Supports multi-region and backup architectures for High availability. ELB is limited to region and does not support multi-region HA architecture.
• supports private Intranet facing DNS service
• internal resource record sets only work for requests originating from within the VPC and currently cannot extend to on-premise
• Global propagation of any changes made to the DN records within ~ 1min
• supports Alias resource record set is a Route 53 extension to DNS.
  • It’s similar to a CNAME resource record set, but supports both for root domain – zone apex e.g. example.com, and for subdomains for e.g. www.example.com.
  • supports ELB load balancers, CloudFront distributions, Elastic Beanstalk environments, API Gateways, VPC interface endpoints, and S3 buckets that are configured as websites.
• CNAME resource record sets can be created only for subdomains and cannot be mapped to the zone apex record
• supports Private DNS to provide an authoritative DNS within the VPCs without exposing the DNS records (including the name of the resource and its IP address(es) to the Internet.
• Split-view (Split-horizon) DNS enables mapping the same domain publicly and privately. Requests are routed as per the origin.
• Routing policy
  • Simple routing – simple round-robin policy
  • Weighted routing – assign weights to resource records sets to specify the proportion for e.g. 80%:20%
  • Latency based routing – helps improve global applications as requests are sent to the server from the location with minimal latency, is based on the latency and cannot guarantee users from the same geography will be served from the same location for any compliance reasons
  • Geolocation routing – Specify geographic locations by continent, country, the state limited to the US, is based on IP accuracy
  • Geoproximity routing policy – Use to route traffic based on the location of the resources and, optionally, shift traffic from resources in one location to resources in another.
  • Multivalue answer routing policy – Use to respond to DNS queries with up to eight healthy records selected at random.
  • Failover routing – failover to a backup site if the primary site fails and becomes unreachable
  • IP-based routing – route traffic based on the IP address of the client making the DNS query
• Weighted, Latency and Geolocation can be used for Active-Active while Failover routing can be used for Active-Passive multi-region architecture
• Traffic Flow is an easy-to-use and cost-effective global traffic management service. Traffic Flow supports versioning and helps create policies that route traffic based on the constraints they care most about, including latency, endpoint health, load, geoproximity, and geography.
• Route 53 Resolver is a regional DNS service that helps with hybrid DNS
  
  • Inbound Endpoints are used to resolve DNS queries from an on-premises network to AWS
  • Outbound Endpoints are used to resolve DNS queries from AWS to an on-premises network
  • Resolver endpoints now support DNS delegation for private hosted zones (June 2025)
• Route 53 Profiles – enables sharing DNS configurations (private hosted zone associations, Resolver rules, and Resolver DNS Firewall rule group associations) across VPCs and accounts using AWS RAM
• Accelerated Recovery (announced Nov 2025) – provides a 60-minute recovery time objective (RTO) for regaining the ability to make DNS changes to public hosted zones during regional disruptions in US East (N. Virginia)
• PrivateLink Support (announced Nov 2025) – allows making changes to DNS infrastructure (hosted zones, records, health checks) without using the public internet

AWS Global Accelerator

• is a networking service that helps you improve the availability and performance of the applications to global users.
• utilizes the Amazon global backbone network, improving the performance of the applications by lowering first-byte latency, and jitter, and increasing throughput as compared to the public internet.
• provides two static IP addresses serviced by independent network zones that provide a fixed entry point to the applications and eliminate the complexity of managing specific IP addresses for different AWS Regions and AZs.
• always routes user traffic to the optimal endpoint based on performance, reacting instantly to changes in application health, the user’s location, and configured policies
• improves performance for a wide range of applications over TCP or UDP by proxying packets at the edge to applications running in one or more AWS Regions.
• is a good fit for non-HTTP use cases, such as gaming (UDP), IoT (MQTT), or Voice over IP, as well as for HTTP use cases that specifically require static IP addresses or deterministic, fast regional failover.
• integrates with AWS Shield for DDoS protection
• uses a global network of 130+ Points of Presence in 95+ cities across 53+ countries
• supports dual-stack Network Load Balancers as endpoints
• supports endpoints in 33 AWS Regions (as of 2025)
• integrates with AWS Load Balancer Controller for Kubernetes (announced 2025)

Transit Gateway – TGW

• is a highly available and scalable service to consolidate the AWS VPC routing configuration for a region with a hub-and-spoke architecture.
• acts as a Regional virtual router and is a network transit hub that can be used to interconnect VPCs and on-premises networks.
• traffic always stays on the global AWS backbone, data is automatically encrypted, and never traverses the public internet, thereby reducing threat vectors, such as common exploits and DDoS attacks.
• is a Regional resource and can connect VPCs within the same AWS Region.
• TGWs across the same or different regions can peer with each other.
• provides simpler VPC-to-VPC communication management over VPC Peering with a large number of VPCs.
• scales elastically based on the volume of network traffic.
• supports security group referencing (announced Sept 2024) – allows creating inbound security rules that reference security groups defined in other VPCs attached to the same Transit Gateway within the same Region.
• supports per-AZ metrics delivered to CloudWatch and Path MTU Discovery (PMTUD) for both IPv4 and IPv6 (announced Nov 2024).
• supports Transit Gateway Flow Logs for monitoring and logging network traffic between transit gateways.
• supports Flexible Cost Allocation (announced Nov 2025) – provides versatile cost allocation options through a central metering policy beyond the default sender-pay model.

Amazon VPC Lattice

• is a fully managed application networking service that connects, monitors, and secures communications between services and resources across VPCs and accounts.
• simplifies service-to-service connectivity without requiring VPC peering, Transit Gateway, or PrivateLink NLBs.
• automatically manages network connectivity and application-layer routing between services across different VPCs and AWS accounts.
• supports connectivity to TCP resources, such as databases, domain names, and IP addresses across VPCs and accounts.
• integrates with AWS IAM for service-to-service authentication and authorization using Auth policies.
• removes the NLB requirement that PrivateLink imposes on providers and supports cross-VPC/cross-account connectivity without CIDR coordination.
• terminates TLS at the data plane so callers do not need to manage certificates.
• provides built-in observability with access logs, connection logs, and traffic metrics.
• Key concepts:
  • Service Network – a logical boundary for a collection of services that can communicate with each other
  • Service – represents an application unit that is independently deployable
  • Target Groups – collection of resources (instances, IPs, Lambda, ALB) for routing
  • Resource Configurations – define TCP resources (databases, IPs, domain names) accessible through VPC Lattice
• Use cases:
  • Microservices connectivity across multiple VPCs/accounts
  • Secure service-to-service communication with zero trust
  • Alternative to VPC Peering and Transit Gateway for application-layer connectivity
  • Replacement for AWS App Mesh (which reached EOL on September 30, 2026)

Amazon VPC IP Address Manager (IPAM)

• is a VPC feature that allows you to plan, track, and monitor IP addresses for AWS workloads.
• organizes IP addresses by routing and security requirements while automating allocation to VPCs, replacing manual spreadsheet-based tracking.
• tracks AWS accounts and VPCs, eliminating IP bookkeeping overhead.
• supports management at both VPC and subnet CIDR levels.
• integrates with AWS Organizations for cross-account IP address management.
• supports provisioning Amazon-provided contiguous IPv4 blocks into publicly scoped regional pools for use with EIPs, NLBs, and NAT Gateways.
• Public IP Insights – free feature that simplifies monitoring, analysis, and auditing of public IPv4 addresses.
• IPAM Policies – define public IPv4 allocation strategies and automate prefix lists.
• integrates with ALB for predictable IP address blocks for internet-facing ALBs (March 2025).
• IPAM Advanced Tier – includes Infoblox integration (Nov 2025) for managing AWS IP addresses through existing Infoblox workflows.

AWS Network Firewall

• is a managed, stateful network firewall and intrusion detection and prevention service for all Amazon VPCs.
• scales automatically with network traffic, requiring no infrastructure management.
• provides Layer 7 firewall capabilities with deep packet inspection.
• supports flexible rules engine for fine-grained control of VPC network traffic.
• provides active threat defense using AWS managed rules to block evasive C2 channels, malicious URLs, and other threat vectors.
• supports Suricata-compatible IPS rules for known bad signatures and traffic patterns.
• includes Network Firewall Proxy for granular security controls to inspect and filter VPC outbound connections, preventing data exfiltration and malware intrusion.
• integrates with AWS Firewall Manager for centralized policy management across accounts.
• can be combined with VPC Lattice for comprehensive security (VPC Lattice for HTTP/S with identity-based controls, Network Firewall for other traffic types).

AWS Cloud WAN

• is a managed WAN service that provides a central dashboard to connect and manage branch offices, data centers, VPN connections, SD-WAN, VPCs, and Transit Gateways.
• uses network policies to create a global network spanning multiple locations and networks, removing the need for different technologies.
• provides a single console and set of APIs to manage networks across AWS Regions.
• supports direct Direct Connect gateway attachments without requiring an intermediate Transit Gateway (announced Nov 2024).
• supports Routing Policy for advanced traffic control (announced Nov 2025) – enables controlled routing environments, minimizing route reachability blast radius.
• supports Service Insertion for inspection and security appliance integration.
• supports PMTUD for both IPv4 and IPv6 (announced Nov 2024).
• supports AWS PrivateLink and IPv6 for management endpoint connectivity (announced March 2025).
• available in AWS GovCloud (US) Regions.

AWS Verified Access

• provides secure access to corporate applications and resources without requiring a VPN.
• implements zero trust principles by evaluating each access request based on user identity and device security posture rather than network location.
• uses the Cedar policy language for defining fine-grained access policies.
• supports secure access to resources over non-HTTP(S) protocols (announced Feb 2025) – enables VPN-less access to TCP-based resources like SSH, RDP, and databases.
• continuously monitors active connections and terminates connections when security requirements aren’t met.
• integrates with third-party identity providers and device management solutions.
• can be used with PrivateLink-backed services to provide authorized internet-based access while maintaining security boundaries.