I don't think the "fake IP" (VPN) is really fixing anything for the end user.

I myself have done ZERO to "fake" my IP.

I get hit with the gateway 502 left and right.

Just refresh a dozen times and it may finally let you in without faking IP.

Or you come back 10 minutes later and do the dozen tries all over again.

It really isn't tied to IP, from what I can see.

The US IP (New York) assigned by VPN enables me to access MSFN successfully. The German IP addresses allocated by my ISP do not. That is a fact. There is no getting round it.

So, after three hours of downtime, I can now access the site from Germany using my German ISP. We’ll see how long this lasts.

So I was able to get onto the site ~4-5 hours ago, and I made a post giving the IP address that had worked for me. But I do not see my post here now. Has someone perhaps deleted it, or was this a ghost post, i.e. it appeared to go through but the gateway error took it out?

I got a bit carried away playing around with the CSF firewall. I set the WAF rules way too strictly. Without Cloudflare, the server needs to be built like a fortress, which is incredibly hard to pull off without causing some collateral damage.

1 hour ago, xper said:

I got a bit carried away playing around with the CSF firewall. I set the WAF rules way too strictly. Without Cloudflare, the server needs to be built like a fortress, which is incredibly hard to pull off without causing some collateral damage.

Sweet! A "fact" that 100% aligns with everyone else's "facts" without arrogantly acting like one fact 'invalidates' the other.

Great work! I think you finally found the REAL ANSWER.

The 502 Bad Gateway problem is caused by Cloudflare. It can take up to 48 hours for all Name Servers (NS) to fully propagate and revert back to the old NS.

6 minutes ago, xper said:

The 502 Bad Gateway problem is caused by Cloudflare. It can take up to 48 hours for all Name Servers (NS) to fully propagate and revert back to the old NS.

Many thanks for all the effort you're putting in to fix this.

Good evening all; nice to finely be again able to converse with you 😉 ; soon after I had posted this (with an Austrian IP) at noon today, I forcibly restarted my router, in the hope that, once again, I could be assigned a Greek IP that works for accessing the board; who would've known? After that, I found myself in an impossible situation where I couldn't visit at all the board, even when using proxy/VPN nodes that previously worked for this purpose 😞 ; I became very frustrated, because I couldn't reply back to xper, with regards to this post of his; apologies, but as you might now understand, I didn't just disregard you 😸 ...

In desperation, I tried many times to connect over the next hours; curious thing was that I did receive e-mail notifications for the topics I was subscribed to (including this one), meaning that some members could still access the board, alas I couldn't visit it myself to reply...

During that time, I did visit one service, that I'm sharing with you, called "websitedown.org":

This made me realise that it probably was a more widespread issue, not just one particular to me; time of the depicted test was ca. 12:17 UTC of Aug 31st...

11 hours ago, xper said:

so it must be something on your side.

The only thing that comes to mind is that ModSecurity is enabled on the server. That shouldn't be the reason, unless there is something suspicious in your browser.

... As things turned out, "my side" was OK 😜 ; and, as I had already reported, the "502" issue was there on every browser, on every PC/laptop/smartphone in my home LAN...

3 hours ago, xper said:

I got a bit carried away playing around with the CSF firewall. I set the WAF rules way too strictly. Without Cloudflare,

37 minutes ago, xper said:

The 502 Bad Gateway problem is caused by Cloudflare.

So, is CF permanently turned OFF now? CF is actually a double-edged sword; necessary for keeping away malicious agents, but when aggressively configured, can also exclude legitimate visitors...

35 minutes ago, skylark53 said:

Many thanks for all the effort you're putting in to fix this.

Ditto, huge thanks @xper , from the bottom of my heart! Fingers crossed, forum access from Greece shall remain uninterrupted in the foreseeable future...

Kindest regards.

There were several things that caused all of this. Cloudflare, proxies, server firewall rules, cached Cloudflare IPs on the DNS servers, my own mistakes, etc.

I hope everything is all right now. For now :-)

17 hours ago, xper said:

The 502 Bad Gateway problem is caused by Cloudflare. It can take up to 48 hours for all Name Servers (NS) to fully propagate and revert back to the old NS.

... and

6 hours ago, xper said:

There were several things that caused all of this. Cloudflare, proxies, server firewall rules, cached Cloudflare IPs on the DNS servers, my own mistakes, etc.

I hope everything is all right now. For now :-)

Thanks for your write-up and explanations 🙂 ; FTR/FYI, here in Greece 🇬🇷 , I'm still being plagued today by the "502 Bad Gateway" problem, at frequent intervals, but quite randomly; to be fair to you though, 48h haven't yet passed since your relevant announcement; to circumvent the problem (with some luck), I have to clear MSFN cookies (logs me out), clear cache, restart browser, reload forum page several times and recite a prayer while doing that 😁 ...

OK, thank you, I've just seen this:

https://msfn.org/board/topic/187878-nameservers-still-propagating/

especially in North America

... "especially in" interpreted as "not just limited to" 😜 ...

Bot attack. There is no way to stop it without Cloudflare, but CF is out of the question, right? So be it.

Totally up to you, pros and cons both ways.
It's all a bit of a mystery to me, to be honest.
ie, financial web sites, Vogons.org, I could list dozens, they don't use Cloudflare but they thwart off the bots "somehow".
I can see the finance sites paying for that bot control. But not other sites like Vogons.org.
So a mystery to me.

22 minutes ago, xper said:

Bot attack. There is no way to stop it without Cloudflare, but CF is out of the question, right? So be it.

Here is a short catalogue of measures to tackle bot attacks, generated by AI:

Effective Anti-Bot Measures for Invision Community (IPS)

To effectively mitigate automated bot registrations and HTTP flooding without relying on aggressive Cloudflare JavaScript challenges (which disrupt older browsers and legitimate user sessions), the following server- and application-level strategies are recommended:

• 1. Custom Q&A Registration Verification Standard reCAPTCHA v2/v3 is routinely solved by modern bot frameworks. Replacing or supplementing it with custom, forum-specific logic questions (e.g., "Which Windows version was released after Windows 2000?" -> "Windows XP") stops automated registration scripts dead in their tracks.

• 2. Integration with StopForumSpam & Project Honey Pot APIs Enabling real-time API checks during registration cross-references incoming IPs, email addresses, and usernames against global spam databases. This silent check drops over 90% of known bot accounts before the registration form is even submitted.

• 3. Disposable Email Address Blocking Implement a dynamic domain blocklist for temporary/disposable email providers. Spambots rely heavily on these services to complete automated email verification loops.

• 4. Nginx / Apache Webserver Rate Limiting (limit_req) Configure rate limiting on critical endpoints such as /register/, /login/, and /search/. If an IP exceeds a reasonable threshold (e.g., more than 2–3 registration attempts per minute), the webserver returns an immediate HTTP 429 (Too Many Requests), preventing PHP and MySQL from being overwhelmed.

• 5. Fail2ban IP-Jailing at the Firewall Level Deploying Fail2ban to parse access logs allows the server to automatically block IPs via iptables if they attempt rapid-fire POST requests to sensitive endpoints.

• 6. Targeted Cloudflare Firewall Rules (WAF) instead of Global Rules If Cloudflare is utilized, avoid global "Under Attack" mode. Instead, set targeted Web Application Firewall (WAF) rules that specifically challenge or block traffic originating from known datacenter ASNs (AWS, DigitalOcean, Hetzner, etc.) or restrict access solely to the /register/ URI, leaving general browsing unaffected.

• 7. New Member Moderation Queue Require manual moderator approval for the first 1–2 posts of newly created accounts. Removing the immediate visibility of spam posts eliminates the incentive for spammers to target the platform.