There is an instance in Amazon EC2 VPC with private IP address only, 192.168.1.100. VPC uses Internet Gateway to get connection to the public network. I've found my IP address using 'curl -s checkip.dyndns.org', let it be 220.127.116.11
Now I need to communicate with 3-rd party team, so that they allow incoming requests from my 18.104.22.168 address on their firewall. I don't want to wake up some day and find out that server can't communicate with 3-rd party API because my ip changed for them and firewall blocks everything from their side.
My main question is: Does public IP address of my instance stay the same for the 3-rd party firewall in case Internet Gateway for VPC doesn't change? Or there is no way to maintain my public IP and the only option is to use either Elastic IP address or NAT Gateway service?