Direct Connect Essentials:

• AWS Direct Connect is a service that provides a dedicated network connection between your network and one of the AWS Direct Connect locations.
• This is done through an authorized Direct Connect Provider (i.e. Verizon or other ISPs).
• Does not require hosting any router/hardware at the Direct Connect Partner location, only requires a Direct Connect location and a participation backbone provider.
• An AWS Direct Connect location provides access to the AWS region it is associated with.
• It does not provide access to other AWS regions.

Direct Connect Benefits:

• Reduce network costs:
  • Reduce bandwidth commitment to corporate ISP over public internet.
  • Data transferred over direct connect is billed at a lower rate by Amazon (data in/out).
• Increase network consistency:
  • Dedicated private connections reduce latency (over sending the traffic via public routing).
• Dedicated private network connection to on-premise:
  • Connect the direct connect connection to a VGW in your VPC for a dedicated private connection from on-premise to VPC.
  • Use multiple VIF (Virtual Interface) to connect to multiple VPCs.
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Cross-network Connection (Cross Connect):

The physical connection between your network and the Direct Connect authorized provider, which then handles the routes and connections to AWS networks.

Private Virtual Interface:

• A Private Virtual Interface allows you to interface with an AWS (VPC).
  • With automatic route discovery using BGP.
  • Requires a public or private ASN number.
• Can only communicate with internal IP addresses inside of EC2.
• CANNOT access public IP addresses, as Direct Connect is NOT an internet provider.
• This is a dedicated private connection which works like a VPN.

• For best practice, use two Direct Connect connections for active-active or active-failover availability.

• You can also use VPN as backup to direct connect connections.

• You can create multiple private virtual interfaces to multiple VPCs at the same time.

Public Virtual Interface:

• A Public Virtual Interface allows you use a Direct Connect connection to connect to public AWS endpoints:
  • Any AWS service (for example, DynamoDB and Amazon S3).
  • Requires public CIDR block range.
  • And even though we are accessing public endpoints, the connection maintains consistent traffic consistency as it is sent over your dedicated network.