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Re: SSH Connection Behind A Router/Firewall

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On 9/8/2016 1:42 PM, Joe wrote:
> On Thu, 8 Sep 2016 12:49:56 -0500
> Tim McDonough <tmcdonough@gmail.com> wrote:
>
>> I have a very straightforward Debian Jessie machine on my network.
>> For SSH it uses the standard/default Port 22 and accessing it via ssh
>> works just fine from anywhere on the local network.
>>
>> I also have a NetGear router configured so that a connection from the
>> outside world using Port 1024 gets forwarded to the local IP and Port
>> 22 on the LAN. My problem is when I attempt a connection from the
>> outside world the connection is refused.
>>
>> Is there another setting on the Debian Jessie system I need to
>> configure or do you believe this is a router configuration problem?
>> If I just allow the forwarding (externally) to forward on Port 22
>> things work as expected.
>>
> No, that should work. As far as the server is concerned, it's a
> standard port 22 job.
That was my thought as well.
> If a router has the option of setting the destination port in a
> forwarding rule, that really ought to work. I've done it in two stages,
> forwarding port A on the public IP, to port B on my firewall/server,
> then to port 22 on an internal machine, no trouble.
I have a NetGear WNDR3800. I have the port forwarding setup as you 
describe.
> Sorry to ask this, but... your ssh client does know it's using 1024,
> doesn't it? Not just the software client, but is there an outgoing
> firewall that also needs to know this? On a modern Windows machine, you
> need to explicitly set up an outgoing rule, it's not just a simple
> stateful firewall any more.
Don't apologize for asking, I'd be perfectly happy if I'd overlooked 
something simple. I'm using a Windows 10 machine to access it and even 
with the firewall in the Win10 box turned off I get the same results.
> Quick check from your network: use Shields Up!! on https://grc.com and
> ask for a check on your specific external port. If the router isn't
> forwarding, or the server isn't responding, the port will show as
> closed. If it shows open, and Mr Gibson lectures you about security,
> then you have a problem at the client end.
The port shows as open.

I initially used PuTTY to test and when I first got the error I also 
tried making an sftp connection with Filezilla. A forwarded port is a 
no-go with either of them.

Thanks for the suggestions,

Tim

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Thread

SSH Connection Behind A Router/Firewall Tim McDonough <tmcdonough@gmail.com> - 2016-09-08 20:00 +0200
  Re: SSH Connection Behind A Router/Firewall Joe <joe@jretrading.com> - 2016-09-08 20:50 +0200
    Re: SSH Connection Behind A Router/Firewall Tim McDonough <tmcdonough@gmail.com> - 2016-09-09 01:50 +0200
  Re: SSH Connection Behind A Router/Firewall Arun Khan <knura9@gmail.com> - 2016-09-12 06:40 +0200

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