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Showing posts from January, 2017

Bypass blocked ports with Reverse SSH Tunneling

Most organisations have security rules that stop non-standard ports on external resources from being accessed from the corporate network. One frequent scenario is when you are running a website on a non-standard port (e.g., 5000 ) on AWS EC2 (e.g., )  and you try to call it from your corporate network. In most cases, if you open your browser and try to access http:// :5000 ,  the site won't load despite having the port open on AWS EC2 Security Group . To overcome this limitation you can use Reverse SSH Tunneling the following way: Open a terminal and navigate to the folder where you have your PEM key to connect to AWS EC2 Type  ssh -i your_key.pem -NL LOCAL_PORT:localhost:REMOTE_PORT ( e.g.,  ssh -i your_key.pem -NL 8080:localhost:5000 ec2-user@ ). Leave the terminal open with the SSH command running. Open on your browser and type http://localhost:LOCAL_PORT (e.g., http://localhost:8080 ). The website wi