Hi,

The easiest setup to install IFS Cloud remotely is when the middle-tier Linux box and Windows management server have unrestricted outgoing access to internet. This and the completely airgapped solution are the only install methods IFS supports. That is, the client has to take responsibility for any other configuration, as incorrectly defined filtering of the traffic often creates problems.

If the outgoing traffic needs to be limited for policy or security reasons, for example a company internal proxy can be used (if exists, not provided or required by IFS).

The proxy install instructions are necessary to make the IFS connection work behind a proxy - proxies act as an intermediary between internet and internal hosts, so that the hosts are not directly connected to internet. You do need setup in the powershell of the management server as well as described by the docs link.

If instead of a proxy you decide to limit outgoing traffic by filtering with a firewall, please see required addresses from https://community.ifs.com/ifs-cloud-faqs-311/frequently-asked-questions-faqs-on-ifs-cloud-remote-deployment-9055 (see item 27).

In addition, connections from the middle-tier (Ubuntu) to Ubuntu security updates (archive.ubuntu.com) AND a connection from the DB server to its security updates (for example yum.oracle.com for Oracle Linux) are required unless another method like a local mirror repository that you constructed is used.
Of course management server security updates (Windows) have to be handled as well. Often times the client has a managed Windows network that this machine may be part of, so it’s likely this is easily handled by the customer. But do check that everything is taken care of to avoid future security holes.

I appreciate your support and do you have clear step to installing proxy for middleware environment please? 

You're welcome.

Are you saying that you are installing the proxy?

That should be the customer's job.

But for example squid on Linux can be used if the separate proxy hist is Linux-based as I would recommend for stability and security.