Azure Logic apps - with a fixed IP address

Question

Hi
We need to call a third party web service (lets call it Destination = point C) - but they only accept traffic from a fixed IP address (or small range) - which they need to whitelist.

We need to make a call to the web service from a Dynamics 365 Portal (point A) . However the portal can have the IP address of any Azure datacentre - and the third party wont whitelist the massive range of possible addresses.

So we are thinking of standing up a web server in the middle (point B) - maybe in Azure - that we can give a fixed IP Address to.
So Dynamics portal (point A) makes a call to the middle web server (B) - which calls the third party web service (C) , returns traffic to B - which they returns the result to A.

Does this sound feasible ?
Could we use Azure logic apps as point B ? if so can a logic app have a fixed IP Address ? or maybe route traffic via some sort of Azure proxy service ?

Any advice appreciated.

Answer 1

You can use a Logic App for this if you have it set up with an Integrated Service Environment: https://learn.microsoft.com/en-us/azure/logic-apps/connect-virtual-network-vnet-set-up-single-ip-address

The ISE is setup inside a virtual network, and the network can have a static IP assigned to it.

What may work better for you is an API Gateway. By default they have a static IP that only changes when you do things like delete and recreate the resource. You could further stabilize it using the same method as the logic app- putting inside a virtual network that has it's own static IP. You would set it up exactly like you are describing for your Logic App. Create an API route that reaches out to the third party service. Dynamics would them call the API management instance to retrieve the data.

Answer 2

You also have the option of going for a standard logic apps. The Paas service provides a set of IPs for each region See https://learn.microsoft.com/en-us/azure/logic-apps/logic-apps-limits-and-config#outbound-ip-addresses
There are around 8 IPs per region. There are different IPs for managed connectors.