sshd + ddclient + home network

[rubidium]

I'm really confused about ddclient.conf and networking in general. What I would like is an overview explanation rather than conf file details. I did spend a lot of time reading documentation and forums, and perhaps if I permute through all the little different conf file suggestions on the forums I will find something that works but I really want to get a basic understanding what I am supposed to do rather than just randomly tweak stuff until it works. Also, if this post gets an answer that works, it will help other people that have a similar set-up (a very common one I think).

So here goes...

I have a home network. My internet connection is via a linksys wireless access point (BEFW11S4). The access point is connected to a dsl modem and is configured to be a firewall and to give out DHCP addresses to the machines in my home network. I guess most things are working: I can surf the web from all my computers, ping other machines, etc. The access point itself receives its dhcp address from verizon which may vary on a daily basis.

The problem is that I want to be able to SSH into my gentoo machine from a remote location.

Here is what I did....

1) I set up openssh. I can ssh to my gentoo machine from the other local machines using the ip provided by the access point. I assume this means that sshd is working and properly configured.

2) I got an ip at dyndns.org: whatever.homeip.net (not actual address)

3) I set up ddclient (carefully piecing together scraps of info from forums and websites) :
emerge ddclient
edited /etc/ddclient/ddclient.conf with my info (*)
edited /etc/init.d/ddclient (**)
rc-update add ddclient default

4) When I ping "whatever.homeip.net" from my local network, I get a response. When I ping it from a remote location I get a timeout. It looks like dyndns.org is supplying the local ip address for whatever.homeip.net. I can also use whatever.homeip.net when I ssh locally and get to my gentoo machine.


So here is where I am confused... what ip address should ddclient get? It looks (from ddclient.conf) that there are several ways to "get" the ip address. And, there are three addresses involved here....

1) whatever.homeip.net --- I want my gentoo machine to appear as though it is at this address on the internet.

2) 220.112.22.23 -- the dhcp address that was given to my linksys access point by verizon.

3) 192.168.1.101 -- the dhcp address that was given to my gentoo machine by the linksys access point. I get this address if I do a "ifconfig"


It looks like a lot of the postings on the forum are assuming that the ipaddress that you get when you do ifconfig is the ipaddress that your computer appears at on the internet.

So, if I set up ddclient such that it gets the ipaddress this way, then ssh works as long as I do it from my local network. If I try ssh remotely, then it fails to connect because 192.168.1.101 means nothing on the internet, right?

If I set up ddclient such that it gets the ip address of the linksys, then I get a real internet ip address (which I can ping). But then ssh does not work. I guess this is because _all_ my machines appear at that ip address on the internet so there is no way to know which one ssh is supposed to connect to, right?

Is there something else on the access point that I am supposed to configure?

Below are my /etc/ddclient/ddclient.conf and /etc/init.d/ddclient files (annotated with my comments):

(*) /etc/ddclient/ddclient.conf
*************************************************

[bmichaelsen]

[rubidium]