I have FreePBX 17.0.19.27 installed using SNGDEB BETA ISO.
I want to turn on Firewall but I cannot find it in Admin menu system.
When I check within modules I see no Firewall module installed. However, there is one firewall module not installed but with description that indicates it is old, meant to be used on RHEL. It has no option to install.
How do I get Firewall?
What firewall is old? What are you seeing?
You’re missing the system admin module which is required for the firewall. What option did you use when you installed the system?
WelI, cannot tell. Maybe I skipped configuring firewall.
But I expect firewall is something that you setup later, when system is up and running.
Do you have the System Admin module installed on your system? When you setup the system did you issue OSO flag which would only install the open source modules?
The firewall won’t work properly without the System Admin module. Is that installed?
System Admin shows nowhere.
I installed PUB using Boot from USB stick.
I have to install from scratch?
Never mind, it’s one of the “spice levels” 
Basically you chose the one that is geared towards legacy hardware like DAHDi/TDM cards, etc. It offers nothing more special.
Do you have any commercial modules installed on the system? Can you download/install the System Admin module from the Module Admin page?
No, I have no commercial modules. I found System Admin module among Commercial but when I try to install it i get this
I wanted to install OSO but it was not on the list so I went with PUB.
I just booted from USB again and found out that when I use Advanced Install then I have OSO.
Is it simpler to just reinstall it again using OSO to get Firewall?
It is quite strange that documentation for FreePBX is so slim. It is like if you already do not know what to do, you are doomed. Almost everything I needed to learn how to do I was unable to find useful info.
The Firewall requires System Admin, which is a commercial (but free to use) module. You cannot do OSO and use the firewall.
I am not sure what that means? I have to buy license to be able to use such vital option?
No because it is free to use.
I found more info here: FreePBX 17 using Debian beta ISO - OSO missing Sysadmin
It seems it indeed is free but we cannot get it because it is commercial module. I guess it is available only with commercial FreePBX. Documentation says nothing about all of this, it actually says that System Admin is standard module and that here is PRO version that is commercial.
Even more, to install System Admin, Firewall module has to be already installed. Firewall module cannot be installed if System Admin is not already installed. Dead loop.
