I have to admit that I am not using Fedora, but I am using Red Hat Enterprise Linux. Your command
ssh user@ip_addr ls
is right on the money. I ran several tests, just to make sure, and the results are:
ssh user@ip_addr ls: works just like it is expected too.
@ip_addr command_requiring_root_privilege: after successful login, I receive "PERMISSION DENIED"
ssh user@bad_ip_addr ls: ssh: connect to host x.x.x.x port 22: No route to host
After trying multiple different commands, I was never able to get the command to fail and give me a ls of the local machine. Is it possible that the directory of the user that you are remoting in as has the same content as you do on the local machine?
Example: Your home directory is on an NFS filesystem on both machines (/nfs_dir/user). if you were in your home directory, and used the command given above (ssh user@ip_addr ls), the "ls" on the remote system would be of the same directory you are in (/nfs_dir/user)
You might try
ssh -vvv user@ip_addr ls
and post the output if you are still having issues. When you do this, also upload
from your local machine.