Confused regarding WCF identity dns value

Question

I'm confused about what the identity element on a client endpoint really does. I've understood that a identity dns value like is supposed to tell WCF to assert that the service's certificate is issued to myserver.local. And that this should allow me to point the endpoint address to https://localhost/MyService.svc instead of https://myserver.local/MyService.svc.

But this fails I don't understand why. I have myserver.local pointing to 127.0.0.1 in my host file and I have self-created certificate issued to myserver.local. It works fine with myserver.local but when I change the endpoint address to localhost it stops working because it "can't establish a SSL/TLS trust".

Can anyone explain why?

Thanks

Solution

If you want to know what the WCF Identity DNS value is for, and what to put in it, see this question:

WCF client endpoint identity - configuration question

It helped me to understand what it's for.