Unable to ssh nodes with global IP

[Rick Sewill]

On Sunday, October 23, 2011 05:14:01 AM Harish Pillay wrote:
> > On 10/23/2011 05:09 PM, Abu Attar Musharih wrote:
> >> The customer service said that  ssh is not allowed. So, what to do
> >> then? I badly need a server with global IP for experimenting grid
> 
> You can do the following:
> a) edit /etc/ssh/sshd_config and change the default port 22 to a
>     higher port say 10022. Actually anything above 1024 would
>     be sufficient.
> b) restart your sshd daemon
> c) from your client, say if you are running on the command line,
>     you can do the following: ssh -p 10022 hostname
>     replacing the 10022 with whatever you've changed your sshd
>     to.
> d) do ensure that on your server you open up the port you want
>     sshd to accept connections. you can do that from the
>     command line via system-config-firewall.
> 
> hth.
> 
> harish

Question to the OP please.  Are you also behind your own router?
Does it run NAT?  If yes, is it configured to forward an ssh connection,
from the Internet, to your local host?

When you switch your ssh server (etc/ssh/sshd_config) to use a non-standard
port, and if you are behind a router that is doing NAT, 
you will need to configure the router to forward the connection to your host.

If you are behind a router, owned by the ISP, that is using NAT,
our suggestions probably won't work...we need to know your network topology.

How can one tell if one is behind a router that uses NAT?
What is your local host's IP address?  
If your host's IP address is in the range, listed by rfc 1918,
http://www.rfc-editor.org/rfc/rfc1918.txt
192.168.0.0 - 192.168.255.255, 172.16.0.0 - 172.31.255.255, 
or 10.0.0.0 - 10.255.255.255, you are behind a router running NAT.