Below Apache directive’s are important to configure reverse proxy.

1. ProxyRequests
2. ProxyPass
3. ProxypassReverse

ProxyRequests:

This directive allows or prevent Apache from functioning as a forward proxy. If you set PorxyRequests to off it doesn’t disable proxypass directive.

ProxyPass:

This directive allows remote servers to be mapped into the space of the local server .In simple language you can call local application from remote servers. The local server doesn’t act as a reverse proxy but it look it remote server’s.

ProxypassReverse:

With the help of this directive Apache can adjust URL Location from reverse proxy server.

<VirtualHost>

...

ProxyRequests Off
ProxyPass /roundcubemail http://192.168.13.48/roundcubemail
ProxyPassReverse /roundcubemail http://192.168.13.48/roundcubemail

ProxyPass /webaccess http://192.168.13.15/webaccess
ProxyPassReverse /webaccess http://192.168.13.15/webaccess

ProxyPass /shellinabox http://192.168.13.18:4200

...

</VirtualHost>

SSLProtocol All -SSLv2 -SSLv3