Hi, I meet a strange problem.
The website architecture is: Internet -- (Proxy server with public and private ip) -- (backend server) Proxy server and backend server are both running Debian buster with apache 2.4.38-3+deb10u3 In the proxy server settings, proxy and proxy_http modules have been enabled, and here I have two example virtual server config: conf.la.conf in proxy server apache: https://pastebin.com/BFxzpnjN http://conf.libreoffice.asia will be redirected to https://conf.libreoffice.asia, which will get from *http*:// intern-conf.libreoffice.asia/ via reverse proxy Notice in the backend part only http is used, SSL module is disabled. The ip of intern-conf.libreoffice.asia is a private ip which is defined in /etc/hosts of the proxy server: https://pastebin.com/gpfsnJ34 This setting works perfectly. However another virtual server setting uses almost the same way, but the behavior is different: limesurvey.conf in proxy server apache: https://pastebin.com/PXs5mbiA http://limesurvey.slat.org will be redirected to https://limesurvey.slat.org, which should get from *http*://limesurvey57.slat.org via reverse proxy where the ip of limesurvey57.slat.org is also defined in /etc/hosts of proxy server like above. But, the real behavior becomes that it will try to find *https*:// limesurvey57.slat.org and got connection refused. I used wget -o- https://limesurvey.slat.org and found that it returns a 302 to https://limesurvey57.slat.org $ LANG=C wget -o- https://limesurvey.slat.org --2020-04-13 19:49:04-- https://limesurvey.slat.org/ Resolving limesurvey.slat.org (limesurvey.slat.org)... 122.116.230.54 Connecting to limesurvey.slat.org (limesurvey.slat.org)|122.116.230.54|:443... connected. *HTTP request sent, awaiting response... 302 Found Location: https://limesurvey57.slat.org/ <https://limesurvey57.slat.org/> [following] * --2020-04-13 19:49:04-- https://limesurvey57.slat.org/ Resolving limesurvey57.slat.org (limesurvey57.slat.org)... 192.168.xxx.57 Connecting to limesurvey57.slat.org (limesurvey57.slat.org)|192.168.xxx.57|:443... failed: Connection ref used. The backend apache virtual config is quite simple: conf.la.conf: https://pastebin.com/J8R9tVb9 limesurvey.conf: https://pastebin.com/igR33iz2 conf.libreoffice.asia works perfectly but limesurvey.slat.org doesn't. I don't know why the reverse proxy behaviors are different. Would anyone please give me some hints? Thanks, Franklin
