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Reverse SSH tunnel to connect to device with dynamic IP

Project owner: Overdrive
Related: [Project Single Boards]
Materials: dynamic IP device aka PICKA, static IP device aka RemoteHost, ssh able to connect between devices by keys
License: Uveďte původ-Zachovejte licenci; CC BY-SA
  • Picka = bannanaPi, raspberryPi, any othere device on dynamic IP
  • RemoteHost = server with static host, Picka can ssh to and you can ssh to that server from anywhere
  • we have some Picka on dynamic IP, but we want to connect to that even we do not know what IP it have at the moment
  • we have RemoteHost, that we can see from anywhere and Picka is able to SSH to that server
  • we will build ssh tunnel from Picka to RemoteHost
  • RemoteHost and Picka should be able to reach each other by certificate, not by passwd

on Picka do

ssh -N -R 2222:localhost:22 serverUser@RemoteHost

explanation of parameters of tunnel:

ssh - shell command
-N do not execute anything when connection successful
-R bind port 22 on remote server [] to 2222 

so now connect to RemoteHost and

ssh -l pickaUser -p 2222 localhost

explanation of functionality

Why did this work? The RemoteHost is listening on port 2222 for incoming ssh connections. If it receives one, it will forward all traffic it receives into the previous ssh connection that was established already. That is essentially what the remote tunnel does.

  • projects/ssh_reverse_tunnel.1465405524.txt.gz
  • Last modified: 2016/06/08 17:05
  • by over23