Comment 1 for bug 1908630

I believe that the default API port is 17070, so 192.168.1.187:17070 should work. With the second and further attempts, you were explicitly telling Juju to call on the wrong port.

I agree that, given a bare IP or domain, Juju should make some guesses about the port, however, or at least include this information in an error message. (The latter is probably safer.)