I have a following specific requirement that I need to setup to access on premise server of one of the payment processor vendor that I am trying to access from EC2 instance. I don't have extensive knowledge about networking so please feel to correct me if I have made mistake in the post.
The specific requirement to achieve this is as illustrated in the diagram,
To do this, I have created a site to site VPN connection that allows me to connect from VPC to the on-premise server using Route Tables, virtual private gateway and customer gateway. Customer gateway being the on-premise server IP address.
Problem, that I am now facing is on way to transform the originating IP address as they expect it to come through 10.250.XX.XX/28 instead of the public IP address of EC2 instance.
I tried setting the Local Address and Remote Address CDR to 10.250.XX.XX/28 and 182.93.XX.XX/27 in site to site VPN, but the result is the same. I even tried setting IPTable rules from the ec2 instance as follows,
sudo iptables -t nat -A POSTROUTING -d 182.93.XX.XX/28 -j SNAT --to-source 10.250.XX.XX
but using this stopped any outgoing request through ICMP ping.
I would really appreciate if you can guide me on resolving this issue and provide hint on if there is any way to achieve this using AWS.
