Unable to discove /connect to my physical linux Server on ASR Replication

Hi Franklyn Hamilton
If you're able to SSH from your own machine (laptop, jump server, or VPN) but the Azure Migrate appliance fails, here’s a structured approach to troubleshoot the issue.

 1. Network Connectivity: Test From the Appliance Itself

 Log in to the Azure Migrate appliance (via RDP or console), then test SSH connectivity:

  Test-NetConnection <your_server_ip> -Port 22

If it fails: You likely have a routing, firewall, or network segmentation issue (VLAN, NSG, UDR, etc.) affecting the appliance, not your laptop.
2. Linux Host Firewall Might Be Blocking the Appliance

 Even if SSH works from your machine, the Linux server firewall might block unknown IPs (including the appliance).

 Check active rules:

Temporarily disable to test:

sudo firewall-cmd --list-all
 sudo iptables -L -n

 Then retry adding the server from Azure Migrate. If it works — the firewall is the culprit.

3. SSH Configuration May Reject the Authentication Type

Ensure the SSH server on your Linux machine accepts the authentication method the appliance is using (typically password-based):

cat/ etc/ssh/sshd_config | grep -Ei 'PasswordAuthentication|PubkeyAuthentication'

Expected config for password auth:

PasswordAuthentication yes PubkeyAuthentication yes

If password authentication is disabled, the Azure Migrate appliance won’t be able to connect unless key-based auth is preconfigured.

4. Username Is Incorrect or Not Properly Configured

 Azure Migrate uses the exact username you provide, and it must:

Verify:

 whoami getent passwd <your_username>

5. Network Path Considerations

Is the Azure Migrate appliance in the same subnet/VLAN as the CentOS server?

Is there a VPN, Bastion, or Jump Host in play that you’re using but the appliance is not? Could there be NSGs, route tables, or firewalls that apply only to the appliance subnet?

Please let me know if you face any challenge here, I can help you to resolve this issue further

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It is successful. I receive a TcpTestSucceeded: True. I also download and installed Putty on my appliance. I was able to use SSH ( non-standard port) and log in as root and supplied password.

Hi Franklyn Hamilton

Thanks for the response.

Can you please provide the username format how you have given in the appliance.

The username is "root". When yu select linux as the physical server you are not given a choice to type in a username. It is pre-populated with root

Does anyone know how the applicance connects to the physical server? over which port?