I discovered that although I haven't even installed iptables, my server was running firewalld. I wasn't even aware it existed. I stopped it, and now I can access my web vandyke.mynetgear.com through my router on port 80 or 443.
I disabled firewalld because I have no idea how to configure it, but my Linksys router is running a firewall that's really easy to configure.
I owe thanks to the correspondents on this list who eventually led me to ask online about Debian firewalls. I knew about iptables, which isn't even installed, but I had never before heard of ufw or firewalld.
-------- Forwarded Message --------
Subject: Re: Web server access
Date: 04/01/2025 05:29:23 PM
On 2/4/25 08:21, Timothy M Butterworth wrote:
Ok so if I understand you correctly then you are attempting to port
forward 80 and 443 through the router's WAN Wide Area Network
interface to a server located in the DMZ DeMilitarized Zone. Does the
server have Apache ACL's, IP Tables or TCP wrapper running on it? Can
you try to do a port ping or use telnet to connect to port 80 to test
connectivity. ex: `telnet <Routers WAN IP Address or Public DNS Name>
80`. As you say that the server is on the inside of your network. Have
you tried placing the server in the DMZ?
Another alternative is the ISP has started blocking incoming connections
on the web ports?
How could I find out if it's doing that?
It's not blocking the random port that I map to 22 so I can ssh to my server.
I can FTP to my server from itself, but not through the router.
I can't FTP to my server from another computer in my house.
And now it seems I can't load web pages from my server on other computers in my house. So maybe the server has started some kind of a firewall. How would I find it and either turn it off or configure it so it allows more than ssh.