We had IPM running under 2.5. I see that the interface has drastically changed. I've been trying to setup a collector and a target and I keep getting a host not responding. I have tried several different sources and keep getting the same error - Source not responding.
Default credentials have no bearing on devices already in DCR. You will need to select the device from the Device Management selector, and click Edit Credentials. Then fill in the correct credentials for that device.