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Confusion over 'ssh' command for networking

asked 2014-12-22 15:38:53 -0600

A.M Dynamics

89 ●37 ●41 ●44

updated 2014-12-22 15:41:15 -0600

Dear All,

I am trying to create a ROS network between two computers. The computer A as master (userA@ComputerNameA:~$) and computer B as client (userB@ComputerNameB:~$). I also set ROS Environment Variables as follow.

On Computer A: export ROS_HOSTNAME= ComputerNameA export ROS_MASTER_URI=http://ComputerNameA:11311

On Computer B: export ROS_HOSTNAME=ComputerNameB export ROS_MASTER_URI=http://ComputerNameA:11311

My problem is when I want to test the network connectivity by SSH command before using ROS packages I get confused and don't know which command I must run on which computer, Master or Client?

For example, If I must run the ssh command on master (computer A), which one of these commands is correct?

1- (userA@ComputerNameA:~$) ssh userA@ComputerNameB or 2- (userA@ComputerNameA:~$) ssh userB@ComputerNameB

Thanks...

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answered 2014-12-22 17:29:02 -0600

Murilo F. M.
806 ●5 ●9 ●20

Regarding the command to run ssh, the user must exist on the remote machine, thus your second command is the correct one.

If you'd like to deepen your understanding of how ssh works, the top hits of a google search for ssh tutorial will come handy.

That said, I would also advise you to export the environment variable ROS_IP for each computer. For instance, for computer A: export ROS_IP=xxx.xxx.xxx.xxx (replacing the x's with computer A's IP address).

You may also find the following two links useful:

ROS/NetworkSetup

ROS/Tutorials/MultipleMachines

I hope it helps.