Se você tiver outro servidor em outro lugar, você pode usar um túnel ssh para acessar o nat e o firewall:
+--------------------------------------------+ ||| +----------------------------------+
| Server at school | ||| | Server outside network |
| 10.2.3.100 | ||| | 1.2.3.4 |
| HTTPD on 80 |--SSH through fw--> | HTTPD 80 proxy -> localhost:81 |
| ssh -R 81:localhost:80 [email protected] | ||| | sshd |
| dns mywebsite.com -> 1.2.3.100 | ||| | dns mywebsite.com -> 1.2.3.4 |
+--------------------------------------------+ ||| +----------------------------------+
^ ^
| |
+--------------------------------------------+ +----------------------------------+
| Client at school looks up mywebsite.com | | Client outside school looks up |
| and connects directly to the server | | mywebsite.com and gets 1.2.3.4 |
+--------------------------------------------+ | which is either served from |
| proxy or forwarded over ssh |
+----------------------------------+