Cant ftp through Voyager router - Help

I've just added a NAS (Safecom) to my network and wanted to use its inbuilt
ftp server. I've configured it on port 21, opened that on the BT Voyager
2100 router/modem , assigned a static ip address to the NAS and port
forwarded 21 from the router to the NAS ip.
The problem is I can't connect from outside. It works fine inside my network
and I can connect and ftp from any of my pc's on my Lan so thats reassuring
to know that the NAS is working but its got me puzzled as to why I can't
connect coming in through the router. Can anyone help?

Cheers

Cedric

"Cedders" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I've just added a NAS (Safecom) to my network and wanted to use its
> inbuilt ftp server. I've configured it on port 21, opened that on the BT
> Voyager 2100 router/modem , assigned a static ip address to the NAS and
> port forwarded 21 from the router to the NAS ip.
> The problem is I can't connect from outside.

Are you trying to connect using the correct address (the router's WAN IP
address)?
Could the ISP be blocking the traffic?
Is a firewall on the router blocking the traffic, so it doesn't get as far
as being forwarded to the server?
Is a firewall on the NAS blocking the traffic?
Are you in fact able to connect but just not able to transfer files?

Alex

"Alex Fraser" <(E-Mail Removed)> wrote in message
news:wvadnTV1Y-(E-Mail Removed)...
> Are you trying to connect using the correct address (the router's WAN IP
> address)?
> Could the ISP be blocking the traffic?
> Is a firewall on the router blocking the traffic, so it doesn't get as
> far as being forwarded to the server?
> Is a firewall on the NAS blocking the traffic?

(Or some other similar configuration on the NAS to restrict allowed
clients.)

I knew I would forget something simple: have you configured a gateway on the
NAS (the router's LAN IP address)?

> Are you in fact able to connect but just not able to transfer files?

Alex

This is weird. A friend can connect via a browser using
ftp://domain.dyndns.org that I set up but can't connect using an ftp client.
At least it shows the router is passing traffic to the right place. I'll
sleep on this and see if inspiration strikes overnight.

Thanks

Cedric.


"Alex Fraser" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed). uk...
> "Alex Fraser" <(E-Mail Removed)> wrote in message
> news:wvadnTV1Y-(E-Mail Removed)...
>> Are you trying to connect using the correct address (the router's WAN IP
>> address)?
>> Could the ISP be blocking the traffic?
>> Is a firewall on the router blocking the traffic, so it doesn't get as
>> far as being forwarded to the server?
>> Is a firewall on the NAS blocking the traffic?
>
> (Or some other similar configuration on the NAS to restrict allowed
> clients.)
>
> I knew I would forget something simple: have you configured a gateway on
> the NAS (the router's LAN IP address)?
>
>> Are you in fact able to connect but just not able to transfer files?
>
> Alex
>

Cedders wrote:
> This is weird. A friend can connect via a browser using
> ftp://domain.dyndns.org that I set up but can't connect using an ftp client.
> At least it shows the router is passing traffic to the right place. I'll
> sleep on this and see if inspiration strikes overnight.
>
> Thanks
>
> Cedric.
>
>
> "Alex Fraser" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed). uk...
>> "Alex Fraser" <(E-Mail Removed)> wrote in message
>> news:wvadnTV1Y-(E-Mail Removed)...
>>> Are you trying to connect using the correct address (the router's WAN IP
>>> address)?
>>> Could the ISP be blocking the traffic?
>>> Is a firewall on the router blocking the traffic, so it doesn't get as
>>> far as being forwarded to the server?
>>> Is a firewall on the NAS blocking the traffic?
>> (Or some other similar configuration on the NAS to restrict allowed
>> clients.)
>>
>> I knew I would forget something simple: have you configured a gateway on
>> the NAS (the router's LAN IP address)?
>>
>>> Are you in fact able to connect but just not able to transfer files?
>> Alex
>>
>
>
Is the router hanging on to the ftp port for its own use? How about
redirecting another port number to the NAS - ie: External port 9021 ->
port 21 on the NAS.

In MsgID<(E-Mail Removed)> on Sat, 17 Mar 2007 23:55:10
-0000, in uk.comp.home-networking, 'Cedders' wrote:

>This is weird. A friend can connect via a browser using
>ftp://domain.dyndns.org that I set up but can't connect using an ftp client.
>At least it shows the router is passing traffic to the right place. I'll
>sleep on this and see if inspiration strikes overnight.

Is your friend using a different FTP client or different settings?

Reason I ask is that for an FTP session, you need *two* connections
between a client and a server, and there are two different ways for the
second connection to be made.

The first connection is the control conntection. Requests for files or
directory listings, in fact all commands, go down this channel. The second
connection is the data connection, any files you request and any directory
listings are sent down this channel.

If the client is set to 'passive' mode (and the server supports it which
most do) then, after the first connection has been made (usually to port
21), the port for the second one is negotiated, and the client opens the
data channel. Your router now has to forward this to your server.

The easier mode to set up at the server end is 'Active' mode. With this,
as long as the inbound port 21 is forwarded to your server, the server
makes the second connection and all your router sees is an outbound
connection from the server machine. However, this way around can give rise
to some users having problems configuring *their* router to forward the
second connection from their public IP to the client machine.

Most routers 'know' about FTP servers and there are various ways of
telling them which machine is running as an FTP server. Once they know
about it they can spy on (interecept and alter) each incoming connection,
with the result that the server 'appears' to the outside world to be
running at the router's public (internet) IP, no matter whether working
through active or passive mode. Have a careful look through the settings
of your internet-connected router.

Dave J.
--
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