How to route TCP traffic through a fixed IP in Azure during local development?

Question

Hello ServerFault Community,

I'm working through a challenge related to accessing a third-party OPC UA server and am considering a solution using Azure's cloud infrastructure.

Background

• Our team needs consistent access to a third-party OPC UA server. My understanding is that this server utilizes TCP for communication.
• The dynamic IP addresses of our local development machines are causing access issues due to the third-party's firewall restrictions. In short: the firewall can only allow some IP addresses that we tell them, but we cannot ask them every couple of days to change them.

Previous Attempts

• I attempted to use a Squid proxy for this purpose. However, I suspect that Squid may not be suitable for handling the TCP traffic required by OPC UA. See this post: https://squid-users.squid-cache.narkive.com/eEVOUnSk/how-to-use-squid-as-a-tcp-forward-proxy

Objective

• Our goal is to configure our network so that all outbound requests from our local development machines consistently appear to originate from one static IP address. This single IP would then be whitelisted by the third-party firewall.
  • To be clear, this is just about making the development process easier, because then we can debug from our own machines in our IDEs. Later, in production, the VM runs behind a fixed public IP address.

Specific Questions

• Does Azure offer a capability to route our TCP traffic, making it appear to come from a fixed IP? If so, I would greatly appreciate specific guidance or links to relevant Azure documentation.
• I am also open to non-Azure solutions. Are there tools or approaches specifically tailored for handling TCP traffic in scenarios like ours? Any recommendations would be highly valuable.

Thank you for your time and assistance!

Answer 1

You can also change the public ips of your VMs in Azure to static ips. Then you don't need to do routing

Another option would be a nat gateway where all devices in a certain subnet go through the nat gateway with one outgoing public ip. https://learn.microsoft.com/en-us/azure/nat-gateway/nat-overview Attach NAT gateway to a subnet to provide outbound connectivity for all private resources in that subnet. All subnets in a virtual network can use the same NAT gateway resource. Outbound connectivity can be scaled out by assigning up to 16 public IP addresses or a /28 size public IP prefix to NAT gateway. When a NAT gateway is associated to a public IP prefix, it automatically scales to the number of IP addresses needed for outbound.