davepass

greetings,

I am attempting to use a service like dyndns so that I can access my Debian (woody) box from the outside world. To do so, I need to find out what my external ip address is. I thought running

#ifconfig

would give me this info but all I can see is the static ip I have assigned it for my LAN, 192.168.1.161.

I have a cable internet connection that uses dhcp. The connection hooks directly to a router with an internal ip of 192.168.1.1, which I set as the gateway for my Debian box. Please let me know if more info is needed about my configuration.

Thanks,

-dave

loft306

look in the routers setup for the public ip ! in that setup it is the router that holds the lease with your isp.

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afrolinux

Here is your external IP.

But one way to do it is using trace route to some external host and looking in the list returned by trace route for the first public IP. This work fine except for some ISPs working with public IPs in their internal network segment.


afrolinux

davepass

thanks to both of you.

Unfortunately all I am able to get is the IP of my router (which is what the little penguin told me).

I may not have read through enough of dyndns's documentation, but I think there is a way to point a dyndns host directly to a specific machine...

any thoughts?

dylunio

You will have to point the dns to the router's IP, and then set the router to forard the port used to the specific computer;

dylunio

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davepass

ok now it's making sense.

My problem is that one machine on my network already has port 22 (ssh) forwarding to its internal, static ip (under a different dyndns host name). Does this mean that no other machines on the LAN can use this port?

afrolinux

As you can specify to the ssh client the port number


You can dedicate arbitary port on the external IP to be forewarded to your internal host at port 22. The only thing is when you connect you have to do it to the external host and have to specify the external port number.

afrolinux

davepass

now i'm confused again

do you mean something like

$ssh -p 55 me@myhost.dyndns.com


Tried this w/port 55 forwarded to 22 and my machine's ip and the connection was refused

davepass

my bad. I was forwarding the port incorrectly within the router. fixed it and same line now works.

Thanks for all the help

afrolinux

I do not know if is used port 55 for anything else but using some port like 55555 will be safe and may be some day a well known port of you@myhost.dyndns.com.

Regards,

afrolinux