On the Overview page of the VM, copy the Public IP address. Open a terminal on your local machine, and SSH to the VM (replace azureuser if you chose a different admin username):
ssh -i [path to your pem file] azureuser@[public IP]
Replace [public IP] with your VM’s public IP address, and [path to your pem file] with the path to your SSH private key file.
When prompted, confirm the connection to add the VM to your known_hosts file.
If you don’t already have an application listening on TCP 8080, you can start one temporarily:
sudo apt update -y && sudo apt install -y python3
python3 -m http.server 8080
Leave this terminal open – the server runs in the foreground.
In a second local terminal run curl to confirm that you can reach the server through the NSG rule you created:
curl http://[public IP]:8080
Replace [public IP] with your VM’s public IP address.
You should see an HTML directory listing (or your application response). A successful response confirms that TCP port 8080 is open and the VM is reachable from the public internet.
To stop the server, press Ctrl + C.
You now have an Arm-based Cobalt 100 VM with port 8080 open and ready to receive external traffic. You can use it to run any test server or deploy your own application.
To learn about optimizing .NET workloads on Cobalt, check out Migrating a .NET application to Azure Cobalt .