My old late friend Dan Kaminsky famously wrote the Perl module "Ozyman DNS", which allowed you to tunnel ssh session over the DNS, thus evading certain firewall

My old late friend Dan Kaminsky famously wrote the Perl module "Ozyman DNS", which allowed you to tunnel ssh session over the DNS, thus evading certain firewalls such as those controlling access to public WiFi. Modern public WiFi setups filter the DNS too, rendering this technique moot, but I remember using "Ozyman DNS" to get WiFi access on the Caltrain and that was highly satisfying. https://boingboing.net/2004/06/21/tunneling-ssh-over-d.html https://boingboing.net/2004/06/21/tunneling-ssh-over-d.html