What is these IPs related to 13.212.3.X

Hello,

The IP's are likely to be AWS edge network IP's or the IP's from the NAT Gateway depending on how have you set up the network & configuration. To answer it exactly, I would recommend you to open up a support case and discuss the same with an AWS engineer, however, the security of the data depends on which services are being used on your end. Are you doing these transactions over the internet or are you involving VPN/CVPN/DX ?

The best bet here would be to open up a support case or discuss the same with your TAM and discuss the scenario with them.

Hope this helps.

Have a look in the EC2 console under "Network & Security / Network Interfaces". You should be able to find those IPs in the table's "Public IPv4 address" column which will tell you more about the resources & services involved.