Hi, I have multi-server setup on debian jessie with ispconfig 3.1.2. I was having problems with email that I managed to resolve by creating the correct dns record entries, however my webserver (web.mydomain.com) now connects then disconnects after a few attempts, I can connect to ISPConfig without disconnection problems by using its internal IP address only, if I use the domain name or public IP address I get : I have checked the site on intodns and get no errors. I have also checked the ip address for conflicts and it also appears ok. I also experience connection problems when using ssh, all servers connect apart from the webserver. I have removed the dns entrys I added for the email problem but the problems persists. I have run netstat -tap and get : Any help is greatly appreciated, thanks
When the internal IP is working and the external IP fails, then the problem might be on your router. And you should check the log files of the server, especially the fail2ban.log file to ensure that fail2ban does not block the IP of the router. Most likely you can not use fail2ban at all on your system as it can not work properly behind routers, so you might have to stop fail2ban.
