Showing results for 
Search instead for 
Did you mean: 
Regular Visitor

Custom Connector: Name resolution fails when going via on-premise



I am trying to connect to a self-hosted web api using the on premise data gateway and a custom connector.

The web api is hosted in Azure in a VNET with no public connectivity. The VM on which the on-premise gateway is installed has access to it that web api (other VM within the same VNET).


When entering the private ip address as api host uri (when setting up the connector), I am getting an error that the the trust relationship cannot be established (self-signed certificate error, signed by our corporate CA and thus not trusted by Flow). So the connection itself is fine, it's only that there is a SSL trust issue, kind of expected.


Then my aim was to use publicly trusted certificates. I read-up on the topic and found out that Let's Encrypt certs are publicly trusted. Also you can get those with a DNS challenge. So I set out to create my own private DNS namespace, deploying a "private DNS zone" in Azure. I created an A Record for the API host as "", mapping to the exact internal ip address.


When RDP'd on the gateway machine, from it, I can ping just fine. But when entering in the custom connector setup-dialogue I am greeted with the error name that the name resolution cannot be done, and thus not being able to find the host.


Does someone have any thoughts on how to go about this? Any help is really appreciated! Thanks.

Community Support
Community Support

Re: Custom Connector: Name resolution fails when going via on-premise

Hi @baouss ,


Could you please explain more details about the error message?


Best regards,



Community Support Team _ Alice Zhang
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Helpful resources


Super User Program Update

Three Super User rank tiers have been launched!


Power Platform 2020 release wave 2 plan

Features releasing from October 2020 through March 2021


New & Improved Power Automate Community Cookbook

We've updated and improved the layout and uploading format of the Power Automate Cookbook!


Power Automate Community User Group Member Badge

Fill out a quick form to claim your user group badge now!

Users online (8,652)