I have a multi-server ispconfig cluster (one machine for email, one for ns, one for control panel and system apps, and one for web and mysql), all machines running debian 8. Right now ispconfig is accessed through server.domain:8080 and I want to make it available via panel.domain (which is a CNAME record pointing to server.domain) without having to use a port number. I tried changing the nginx vhost config for the control panel but I found I couldn't log in, I got no error message on the login web page or in the logs, but the login page was just redisplayed. Switching the vhost config back allows me to log in again. What have I missed? Is is possible to configure ISPConfig this way? Thanks.