Hi @Seth Spearman,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
- The error message "The target machine is either currently unreachable or username/password is not correct" usually indicates that there is an issue with the credentials, or the target machine is not reachable.
- Please make sure that you have entered the correct username and password for the target machine. Also, ensure that the target machine is running and is reachable from the Azure Bastion host. You can try to ping the target machine from the Azure Bastion host to verify the connectivity.
- If the issue persists, you can try resetting the password for the target machine and try again.
- You can check your NSG on the VM subnet or nic whether you are allowing inbound access from Bastion subnet to your VM.
- Please check if you have any firewalls or any network configuration changes that could have occurred recently impacted this.
- You can troubleshoot your connectivity issues by navigating to the Connection Troubleshoot tab (in the Monitoring section) of your Azure Bastion resource in the Azure portal. Network Watcher Connection Troubleshoot provides the capability to check a direct TCP connection from a virtual machine (VM) to a VM, fully qualified domain name (FQDN), URI, or IPv4 address.
Reference: https://learn.microsoft.com/en-us/azure/bastion/troubleshoot#connectivity
Kindly let us know if the above helps or you need further assistance on this issue.
Regards,
Sai Prasanna.