how to do auth forwarding to backend entry in Traefik 1.7

Traefik Traefik v1
,
1

Traefik 1.7
Docker
Spring Boot

I need to use the auth forwarding capabilities of Traefik.

My auth endpoint is exposed by a spring boot component behind the Traefik and exposed as "backend-authentication" with URI "http://123.1.23.5:8081" in Traefik Dashboard.

In my configuration, traefik routes everything from "http://api-dev.mycompany.com" to backends API using "PathPrefix" rules.
Therefore my authentication component is available as "http://api-dev.mycompany.com/authentication"

When I do auth forwarding like this:

[entryPoints]
    [entryPoints.https]
        address = ":443"
        [entryPoints.https.auth.forward]
            address = "http://api-dev.mycompany.com/commerce/authentication/v1/ldap/auth"
            trustForwardHeader = true
            authResponseHeaders = ["Authorization"]

Traefik goes through endless forwarding loop.

When I use the following configuration it is working as wanted:

[entryPoints]
    [entryPoints.https]
        address = ":443"
        [entryPoints.https.auth.forward]
            address = "http://123.1.23.5:8081/commerce/authentication/v1/ldap/auth"
            trustForwardHeader = true
            authResponseHeaders = ["Authorization"]

I would like to use a service name related to the backend-authentication as seen in Traefik dashboard but when I try that configuration:

[entryPoints]
    [entryPoints.https]
        address = ":443"
        [entryPoints.https.auth.forward]
            address = "http://backend-authentication/commerce/authentication/v1/ldap/auth"
            trustForwardHeader = true
            authResponseHeaders = ["Authorization"]

I ran into error 500.

I do need the capability to use logic name and not IP as there are subject to change.

I cannot run the component on another port or another network... Any idea would be apreciated.