Permissions Denied - After successful connection as 'root' ONLY when connecting externally

Question

So, I have been using Ubuntu Server 12.04.01 for the past couple of weeks after using Ubuntu Desktop 13.10 for about a couple of months and find it a refreshing start after switching over from the Windows environment types.

All is good except for a one thing that I have been troubleshooting for some time and for the life of me, can not figure out.

I have open-ssh installed on my Ubuntu server and I am able to successfully connect to it via SSH using Windows’ client putty program on port 22 (default). The only changes I have made are to my sshd_config file located on my server in the /etc/ssh/ directory. The config info is also listed with the other info (if there is any other info that I can provide that may help out, let me know).

Version of SSH installed:

root@juggernaut:~# dpkg -l | grep "ssh"
ii  openssh-client                     1:5.9p1-5ubuntu1.3         secure shell (SSH) client, for secure access to remote machines
ii  openssh-server                     1:5.9p1-5ubuntu1.3         secure shell (SSH) server, for secure access from remote machines
ii  ssh-import-id                      2.10-0ubuntu1              securely retrieve an SSH public key and install it locally

Permissions on /:

root@juggernaut:~# ls -lah /
total 84K
drwxr-xr-x 22 root root 4.0K Jan  2 06:49 .
drwxr-xr-x 22 root root 4.0K Jan  2 06:49 ..
drwxr-xr-x  2 root root 4.0K Jan  2 06:45 bin
drwxr-xr-x  3 root root 4.0K Jan  2 06:52 boot
drwxr-xr-x 14 root root 4.0K Jan  2 13:44 dev
drwxr-xr-x 88 root root 4.0K Jan  3 18:25 etc
drwxr-xr-x  3 root root 4.0K Jan  1 17:59 home
lrwxrwxrwx  1 root root   37 Jan  2 06:49 initrd.img -> /boot/initrd.img-3.2.0-74-generic-pae
lrwxrwxrwx  1 root root   37 Jan  1 15:08 initrd.img.old -> /boot/initrd.img-3.2.0-29-generic-pae
drwxr-xr-x 18 root root 4.0K Jan  2 06:44 lib
drwx------  2 root root  16K Jan  1 15:03 lost+found
drwxr-xr-x  3 root root 4.0K Jan  1 15:07 media
drwxr-xr-x  2 root root 4.0K Aug  3  2012 mnt
drwxr-xr-x  2 root root 4.0K Jan  1 15:04 opt
dr-xr-xr-x 80 root root    0 Jan  2 13:44 proc
drwx------  4 root root 4.0K Jan  3 18:25 root
drwxr-xr-x 15 root root  540 Jan  3 18:25 run
drwxr-xr-x  2 root root 4.0K Jan  2 06:48 sbin
drwxr-xr-x  2 root root 4.0K Mar  5  2012 selinux
drwxr-xr-x  2 root root 4.0K Jan  1 15:04 srv
drwxr-xr-x 13 root root    0 Jan  2 13:44 sys
drwxrwxrwt  3 root root 4.0K Jan  3 18:17 tmp
drwxr-xr-x 10 root root 4.0K Jan  1 15:04 usr
drwxr-xr-x 12 root root 4.0K Jan  2 13:43 var
lrwxrwxrwx  1 root root   33 Jan  2 06:49 vmlinuz -> boot/vmlinuz-3.2.0-74-generic-pae
lrwxrwxrwx  1 root root   33 Jan  1 15:08 vmlinuz.old -> boot/vmlinuz-3.2.0-29-generic-pae    

But when I connect to my server as root successfully within the LAN (internal network), I have full access to every location within my server via ssh, as if I was connected at the server console itself.

But, when I am connect to the server via SSH externally via my public IP/network’s hostname, I only get a

$

As a prompt after successfully logging in as root – no banner, motd, NOTHING ELSE like I would if I had connected to the server on LAN. With that said, I can browse a just about every location and stuff, but when I ‘cd’ to the ‘/etc’ directory, I get the message:

ls: can’t open ‘.’: Permission denied

I have done my due time by searching the web, but to know luck. Hopefully there is some MINOR setting I am missing.

Answer 1

1. Made a remote connection (from a external source) via SSH.
2. After successfully logging in a root, performed the ifconfig command.
   • Noticed immediately that the IP address was infact the LAN IP addess of my gateway router.
3. The next step was disabling the port forward I THOUGHT was correctly setup.
4. I attempted to reconnect again (from a external source) via SSH -- and behold, I am still able to connect.
5. Did step 2 of this list again and same info! (Now I'm getting somewhere -- thanks Chris Nava)
6. Now, I disable SSH to the gateway router (I had set this up previously without remembering it was enabled).
7. I once again attempted to reconnect again (from a external source) via SSH -- I get a timeout notification.
8. So far so good -- I re-enable port forwarding to the SSH server and BAM! All problems solved.

Well, goes to show, that if your not using it, DISABLE IT! Learned my lesson the hard way.