Global Infrastructure

AWS

• AWS has regions, Each Region has atleast 3 availability zones (AZ)
  
• Local Zones: Refer Here
• Wavelenght Zones: Refer Here
• AWS Global Network connects every region,local zones, edge locations privately

AWS VPC (Virtual Private Cloud)

• This is a service offered by AWS to create virtual networks .
• VPC can be used to create a virtual network scoped to a region
• Subnet belongs to an AZ and this is where the infrastructure is connected
  
  
• In AWS every region has a default vpc already created.
• note: never make changes in default vpc, for your customizations always create a new vpc
• In AWS when we create a vpc, we get a default route table (router) and all the vpc will be private without internet connections.

AWS VPC Components

• Subnets
• Route tables (Router):
  • This acts as a router where we can configure rules for routing
  • Every vpc will have a default router which is configured to enable all internal communications within vpc
• Internet Gateway (Dual Internet connectivity): This gives dual connectivity, subnets in vpc can be configured via router to communicate with/from internet, This makes public ips work.
• Egress only Internet Gateway (Uni directional Connectivity): This gives intenet connectivity, subnets in vpc can be configured via router to communicate with internet
• Restrictions (Firewall):
  • Security Groups
  • Network ACLs
• Elastic IP Address: This refers to a public ip
• NAT Gateway: AWS gives options to create public subnet and private subnets. To enable internet access for private subnets we need NAT Gateway

Lets create a vpc and an ec2 instance

• Create vpc with two subnets in different zones
  • subnet1
  • subnet2
• For screen shots refer classroom video
• Use resource maps
  
• Lets create an ec2 instance with public ip address
  
• Now try ssh connectivity it will not work
• Now configure default route table to forward traffic to internet gateway
  
• Now retry ssh connectivity
  
• Overview
  
• Any subnet which is connected to a route table which has route to internet gateway is referred as public subnet.

Filtering traffic by ip addresses

• Restrictions on ip or finding ip can happen by using network id part of ip address
  • a network with range 10.10.0.0 to 10.0.0.255 => 10.0.0.0/24
  • to all ips 0.0.0.0/0
  • specific ip address 100.100.100.100/32

Azure

• Azure has two types of Regions
  • Regions with zones (3)
  • Regions without zones
    
• Azure Extended zones Refer Here
• Azure Back bone network onnects every region, edge locations privately

Azure Virtual network (vnet)

• This is a service offered by Azure to create virtual networks.
• Azure virtual network is scoped to a region
• subnets are also scoped to a region
• while creating infra elements we can select zones
  
  
• In Azure when we create a virtual network, routing happens with default routes (a router), internet access is available for both inbound and outbound