About Firewalls
All Rails Machine VPS plans are protected by a shared Cisco firewall. All incoming ports are blocked except ssh, dns, ftp, http/https, smtp, imap, pop3, and 8000-10000. You can close down additional ports using iptables.
To access ports on your server that are firewalled, the best approach is to use ssh to tunnel the connection to your local computer. See Connecting To My SQL for an example.