The close reason looks so:
"Questions on Server Fault must be about managing information
technology systems in a business environment. Home and end-user
computing questions may be asked on Super User, and questions about
development, testing and development tools may be asked on Stack
This StackExchange site, the ServerFault is unique that its topic is not about specific technologies, but on their usage. I.e. you can ask the same question about a business network or from a home network, and the second will be offtopic and the first won't be. Although business and home networks have mostly different problems and characteristic technologies. For example, a question like "How can I download Youtube videos?" is clearly not a question about a business network. I think your question is not such a clear case.
In my opinion, some more lenience would be useful on the site, but which question is ontopic and which is not, it is decided by community votes. Diamond mods have decisive votes. They aren't too many.
In theory, these votes aren't too much and most questions are closed or reopened by the community. In the practice of the ServerFault, currently the close/reopen voters seem to be inactive, thus the mods are trying do also their tasks, and the site is undermoderated (relevant stat).
It results that the (painful) closure and the (happy) reopen decisions are often single-person actions, and these are much lesser defensible.
Sometimes I used already port forwarding in production environment, although as I can remember, I never used it for proxying http. I did http proxy always in single frontend - multiple backend setups. But I personally disagree @Sven 's explanation, I can imagine a portforwarding setup in a business environment, mainly in your case: if there is a development infrastructure with a crap router, and its upgrade is impossible because company restrictions. In your case, I would scrap the router and I would make the correct hosting with a Linux PC.
A "business environment" shouldn't mean a Big Company where you can call some IT Department if there is a configuration need on your dev hosting or company firewall. I think a small-to-medium sw development company is also a business environment. But it is my opinion, and in theory, it could be decided by votes (although it would be likely a closure).
What you can do:
- Get to 3000 rep as soon as possible, and help the site to revive. On this site, it is easy, but my experience is that we hit here more often some debatable rules.
- Here is the list of all technological sites of the SE Network, find a sympathetic one and re-ask your question there. I think your question would have a much higher chance to survive the voting on the Unix SE or on the SU.
P.s. your config shows that you likely don't differentiate between the IP and the name-based virtualhosting. You don't need
ServerName in the apache config if there is only an IP-based virtualhost.