Skip to content

VPC Router

Characteristics

  • Virtual Router within a VPC
  • Highly Available - across all AZs in that region
  • Scalable - no performance management required
  • Routes traffic between subnets
    • also routes EXTERNAL networks INTO the VPC
    • also routes VPC into EXTERNAL networks
  • Router has interface in every subnet - subnet+1 address (default GW via DHCP option set)
  • Controlled using route tables

vpc-router

Route tables

  • Route tables for your VPC
  • Every VPC is created with a Main route table (RT)
    • also defaults for every subnet in the VPC
  • Custom route table can be created and associated with subnets in the VPC which removes the Main RT from the subnet
  • Subnes are associated with One RT (Main or Custom)

  • Main RT should be left as it is and Custom Route Tables should be created for any customization

    • to ensure default association of subnet does not get default RT

  • Route tables contain routes

    • most specific routes first
    • static routes are added and update manually
    • if route propagation is enabled, routes are automatically added called propagated routes
    • 🔴 Limitation 🔴 = 50 static routes and 100 dynamic/propagated routes
    Priority Route Type/Condition
    1 Longest Prefix
    2 Static Routes
    3 Propagated Routes
    1. DX
    2. VPN Static
    3. VPN BGP
    4. AS_PATH

  • RT's can be associated with gateways- IGW or VGW

  • IPv4 and IPv6 are handled seperatly within a RT
  • Routes send traffic based on destination to a target


vpc-routing