Internal web API Call

Question

Hi, 
 When I call a web API from another web API within the same server, the external url parameter value of the final web API iin the httppost request doesn't seem to work but I have to give the localhost url - like this :localhost:8080/.../webapiname. Why is that and will this work in all environments? I understand it is not ideal to call this way, but I a little confused as to why the direct url is not working.

Stefan Helzle · Accepted Answer

This looks like an issue with local DNS resolution. I suggest to contact your sys admins.

Mathieu Drouin · Answer

If the FQDN doesn't work, that means the machine can't resolve that domain. As I mentioned before, there are 2 possibilites: 
 1. There is an issue with DNS resolution on the host machine. 
 2. There is a firewall preventing communication to the outside.

almuqeets268991 · Answer

This usually happens because external URLs route through DNS, public IP, and network security layers. In many setups, an SMS firewall or network firewall can block or restrict these loopback requests. 
 localhost works because it bypasses those layers and stays inside the server. 
 But this isn&rsquo;t reliable for all environments, especially in cloud or microservices setups. Best practice: Avoid internal HTTP calls and use direct service communication.

Internal web API Call

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