Login cPanel Ports: 2082, 2083(SSL)
Login webmail Ports: 2095, 2096(SSL)
If your webserver’s gateway has blocked the ports above, you can’t login cPanel as usual, well, here is the solution to fix it: make your domain A record to cpanel.yourdomain.com and webmail.yourdomain.com plus their corresponding IP, ok now, they will work well with port 80.