Re: AS400 to Internet through Proxy server.

Gerald,

Funny you should ask. I've just been deep into FTP proxy server issues.
Here is a general overview.

As you noted the proxy server stands between your FTP client and the FTP
server you are going to. It does address translation, port mapping, etc.
But this creates a little problem for the FTP client. The FTP client
actually has two connections to the server. One for commands and one for
data transfer. It is usually the server that opens the connection back
to the client for data transfer. But you have a proxy server in the
middle that foils this attempt. 

To solve this the client has to go into "passive" mode. This means that
the client will actually open both the control and data transfer
connections. This lets the proxy server negotiate both with the intended
server.

In V4R2 IBM implemented passive mode with the SENDPASV FTP subcommand.
You issue this command before doing a PUT, GET, LS, or other operation.
When SENDPASV is executed the FTP client will operate in passive mode.
Remember to issue this before each command that transfers data.

Hope this helps!
Patrick
-- 
IBM AS/400 communications, FTP automation, and network security
software and consulting services.

http://www.patownsend.com

Gerald Magnuson wrote:
> 
> I have just installed an ISDN line and Router onto my internal network.
> Works great.
> Our company has both an Internal IP network, and a list of External IP
> addresses.
> I have bound an outside IP address to an interface on the AS400.
> I then created a default route to the router.
> Works great. I can now see the outside world from the  AS400, and
>  the outside world can see my AS400.
> 
> However, I want my router directly connected a proxy server and not
> directly connected to the network backbone. ( I do not want an external
> IP address for my AS/400)
> 
> The proxy server will have a IP address on our internal network and
> perform IP translation to the outside world.
> 
> I tried to create a route to the Router with out the Outside IP address
> interface, but could not.
> 
> What is needed to get the AS400 to FTP to an Outside site through
> a proxy server?
> 
> Gerald Magnuson
> The Knapheide Manufacturing Company
> Quincy Illinois
> 
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