Azure Site Recovery (ASR) - CS registration with Azure vault has failed. Failed to register DRA. Error code:1.

I've recently started to play with Azure Site Recovery (ASR) to migrate our internal VMware VMs up to Azure.

During the install process, I received the following error: CS registration with Azure vault has failed.

I attempted to register the vault through the configuration server app and was prompted with the following: Failed to register DRA. Error code:1.

According to the logs possible solutions are:

1) Internet connection failure or Invalid/expired vault credentials file. Verify the proxy settings, regenerate the vault credentials file and retry the operation with the updated credentials file.

2) Machine being out of sync from the time zone. Ensure that your current machine time corresponds to the selected time zone.

It turns out, routing wasn't set up to use the ExpressRoute to get to Azure resources.

Troubleshooting: While attempting to register ASR through the config server app, run netstat -na in the command prompt to see if there are any entries with SYN_SENT

Once that was sorted, I was relieved to see: