Simple port forwarding problem

Hi,

I'm afraid I am a complete beginner at this...

I have a Debian Linux box sitting behind a Linksys WRT54GS wireless
router. It is running the SSH daemon listening on port 22. The router
is serving IPs under DHCP and the Linux box has an IP of 192.168.1.103.
I checked the external IP using one of those 'check my ip' sites and
it is 82.xxx.xxx.xxx. Both IP's are still the same, as the Linux box
and the router have never been switched off and haven't reset/crashed.

I am able to SSH into the Linux box from any of the computers on the
local network (i.e. on the same side of the router).

I have set up port forwarding on the router [Port Start]=22 [Port
End]=22 [Direction]=both [Destination]=192.168.1.103 [Enabled]=Yes.
However, I get no response when I "Putty -ssh 82.xxx.xxx.xxx". I also
get no response from "ping -ssh 82.xxx.xxx.xxx".

I would be very grateful if someone could give me some pointers on how
to diagnose the source of this problem.

Many thanks

Jon



jrpfinch

On 24 Nov 2006 01:06:53 -0800, "jrpfinch" <(E-Mail Removed)> wrote in
<(E-Mail Removed) .com>:

>I'm afraid I am a complete beginner at this...
>
>I have a Debian Linux box sitting behind a Linksys WRT54GS wireless
>router. It is running the SSH daemon listening on port 22. The router
>is serving IPs under DHCP and the Linux box has an IP of 192.168.1.103.
> I checked the external IP using one of those 'check my ip' sites and
>it is 82.xxx.xxx.xxx. Both IP's are still the same, as the Linux box
>and the router have never been switched off and haven't reset/crashed.
>
>I am able to SSH into the Linux box from any of the computers on the
>local network (i.e. on the same side of the router).
>
>I have set up port forwarding on the router [Port Start]=22 [Port
>End]=22 [Direction]=both [Destination]=192.168.1.103 [Enabled]=Yes.
>However, I get no response when I "Putty -ssh 82.xxx.xxx.xxx". I also
>get no response from "ping -ssh 82.xxx.xxx.xxx".
>
>I would be very grateful if someone could give me some pointers on how
>to diagnose the source of this problem.

Check the router log to see what's happening when you try to SSH in from
the outside. Your ISP may be blocking port 22. Try a different port.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

jrpfinch wrote:

> However, I get no response when I "Putty -ssh 82.xxx.xxx.xxx". I also
> get no response from "ping -ssh 82.xxx.xxx.xxx".
>
Hi,
I know this probably sounds silly, but you wont be able to do this from
*inside* the LAN.
You might have to ask a friend to do the putty 82.xxx.xxx.xxx from
outside your network over the internet.
*Then* you will be able to check the logs as John has pointed out.

Regards,
Shiv

outbackwifi <(E-Mail Removed)> wrote:
> I know this probably sounds silly, but you wont be able to do this from
> *inside* the LAN.
> You might have to ask a friend to do the putty 82.xxx.xxx.xxx from
> outside your network over the internet.
> *Then* you will be able to check the logs as John has pointed out.


I have a Linux AS3 and ES4 dual boot server available on a simple
Netgear router. I can reach the "outside" address from inside.
I have ssh, and some other ports, redirected to the Linux box.

I wonder if the local firewall rules in the Linux box are set to allow ssh
access from outside the LAN?

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

On Sat, 25 Nov 2006 17:59:00 +0000 (UTC), (E-Mail Removed) wrote in
<eka094$snr$(E-Mail Removed)>:

>outbackwifi <(E-Mail Removed)> wrote:
>> I know this probably sounds silly, but you wont be able to do this from
>> *inside* the LAN.
>> You might have to ask a friend to do the putty 82.xxx.xxx.xxx from
>> outside your network over the internet.
>> *Then* you will be able to check the logs as John has pointed out.
>
>I have a Linux AS3 and ES4 dual boot server available on a simple
>Netgear router. I can reach the "outside" address from inside.

Many low-end routers won't do that.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

There is no firewall on the Linux box. I have changed the ssh config
file so that it listens on port 14000 instead. Still no luck.

I'll wait till I get home this evening to see what the router log
says...

I've changed the ssh daemon to listen on port 14000 instead and have
also told the router to forward in both directions on port 14000.
"putty -ssh -P 14000 82.xxx.xxx.xxx" from outside the LAN still yields
no response. Will check the router log when I get home this evening...

jon

Can you connect to a redirected port for some other utility?
I might test a redirection of http or daytime, or some useful tool like
iperf. iperf could be run on some other system on your LAN, so you could
prove that redirection works to a box other than Linux.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5