Hi Alfredo CREGO,
Thank you for reaching out to us on Microsoft Q&A forum.
From your question we understand that you are trying to complete the exercise from Describe Azure compute and networking services
We have tried to perform the exercise from our end and successfully completed.
When we run the following command (curl --connect-timeout 5 http://$IPADDRESS) please find the below screenshots for your reference:
Please try to follow each step from the given exercise. We suggest you start the lab from the beginning and complete the steps as mentioned in the exercise. Wait for each command in the exercise to execute completely.
As mentioned by you, the company proxy or firewall will prevent from reaching the IP address and port depends on your company firewall settings. Kindly reach out to your company admin to check about the restrictions.
If the company firewall settings are enabled, we request you to avoid the company network, devices or VPN. Try with your own environment credentials.
Please don't hesitate to reach out to us if you have any other queries with screenshots of the error.
If the information is helpful, please Upvote & Accept Answer so that it would be helpful to community members.
Thank you.