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IPv6 & Egress Internet Gateway

Links: 101 AWS SAA Index

IPv6

  • All IPv6 addresses will be internet-routable which means there will be no private IP addresses.
  • IPv4 cannot be disabled for your VPC and subnets but IPv6 can.
  • We can enable IPv6 (they're public IP addresses) to operate in dual-stack mode
  • Your EC2 instances will get at least a private internal IPv4 and a public IPv6
  • So, if you cannot launch an EC2 instance in your subnet then it's not because it cannot acquire an IPv6 (the space is very large). It's because there are no available IPv4 in your subnet. Solution is to create a new IPv4 CIDR in your subnet.
  • To get IPv6 addresses you need to enable IPv6 CIDR in VPC. By default they are disabled.

Egress Only Internet Gateway

  • They are used for only IPv6 traffic.

  • They are similar to NAT Gateway but for IPv6.

    • It allows the instances in the private subnet to initiate outbound connections over IPv6 while preventing the internet to initiate an inbound IPv6 connection. Same level as Internet gateway.
      • attachments/Pasted image 20220430210806.jpg
    • Although it works similar to NAT gateway it is at the VPC level (similar to internet gateway) whereas NAT Gateway is in the public subnet. It makes sense since in IPv6 we don't need NAT (network address translation) since we don't have any private IP addresses.
    • attachments/Pasted image 20220430210645.jpg

  • Route tables of the private subnet must be updated for this.

Last updated: 2023-03-09