Hi All,
Newbie question. I posted this on Stack Overflow but haven't gotten any replies yet. https://stackoverflow.com/questions/63391424/why-do-i-get-connection-timeout-on-ssl-even-though-nginx-is-listening-and-firewa

Most/many visitors to my site https://example.org get a connection timeout. Some visitors get through, possibly ones redirected from http://example.org or those who've previously visited the site.

I'm trying to determine if this is a firewall issue or an nginx configuration issue.

Firewall

I'm using UFW as a firewall, which has the following rules:

To Action From
-- ------ ----
SSH ALLOW Anywhere
Nginx Full ALLOW Anywhere
80/tcp ALLOW Anywhere
443/tcp ALLOW Anywhere
SSH (v6) ALLOW Anywhere (v6)
Nginx Full (v6) ALLOW Anywhere (v6)
80/tcp (v6) ALLOW Anywhere (v6)
443/tcp (v6) ALLOW Anywhere (v6)

I could give some relevant rules from iptables if anyone needs that, but I'd need some direction on what to look for.

For sudo netstat -anop | grep LISTEN | grep ':443' I get

tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 120907/nginx: worke off (0.00/0/0)
tcp6 0 0 :::443 :::* LISTEN 120907/nginx: worke off (0.00/0/0)

Not sure what "worke off" means.

nginx

It's a virtual host with the server name myservername.com which serves up two websites, example.org and example.com/directory. Example.org points to a docker container running eXist-db. Example.com/directory is serving up a directory on localhost:8080 proxied from another server where example.com lives. Example.com/directory is running smoothly on https when I access it in the browser -- I presume this is because it actually talks to the example.com host over http.

Example.org and myservername.com both have certs from let's encrypt generated by certbot.

When I try nmap from my local machine I get some results I can't explain. Notice the discrepancy between ports 80 and ports 443 and between IPv4 and IPv6

$ nmap -A -T4 -p443 example.org
443/tcp filtered https

$ nmap -A -T4 -p443 my.server.ip.address
443/tcp filtered https

$ nmap -A -T4 -p443 -6 my:server:ip::v6:address
443/tcp open ssl/http nginx 1.10.3

$ nmap -A -T4 -p80 example.org
80/tcp open http nginx 1.10.3

$ nmap -A -T4 -p80 my.server.ip.address
80/tcp open http nginx 1.10.3

My nginx.conf is

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
worker_connections 768;
# multi_accept on;
}

http {

##
# Basic Settings
##

client_max_body_size 50M;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;

server_names_hash_bucket_size 64;
# server_name_in_redirect off;

include /etc/nginx/mime.types;
default_type application/octet-stream;

##
# SSL Settings
##

ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
ssl_prefer_server_ciphers on;

##
# Logging Settings
##

access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;

##
# Gzip Settings
##

gzip on;
gzip_disable "msie6";

# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

##
# Virtual Host Configs
##

include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}

and my nginx server blocks:

server {
listen 80 default_server;
listen [::]:80 default_server;

server_name _ myservername.com;
return 301 https://myservername.com$request_uri;
}

server {
# SSL configuration
#
listen 443 ssl default_server;
listen [::]:443 ssl default_server;

server_name _ myservername.com;

location / {
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_pass http://localhost:8080;
}

ssl_certificate /etc/letsencrypt/live/myservername.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/myservername.com/privkey.pem;
}

server {
listen 80;
listen [::]:80;

server_name example.com www.example.com;

gzip off;

location / {
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_pass http://localhost:8080;
}
}

server {
listen 80;
listen [::]:80;

server_name example.org www.example.org;
return 301 https://example.org$request_uri;
}

server {

# SSL configuration
#
listen 443 ssl;
listen [::]:443 ssl;

server_name example.org www.example.org;

gzip off;

location / {
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_pass http://docker.container.ip.address:port/exist/apps/example/;
}

location /workshop2020/ {
return 302 http://example.org/forum2020/;
}


location /exist/apps/example/ {
rewrite ^/exist/apps/example/(.*)$ /$1;
}


ssl_certificate /etc/letsencrypt/live/example.org/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/example.org/privkey.pem; # managed by Certbot

}

Very grateful for any help!!
Nathan