RE: telnet

["Lim Hock-Chai" <Lim.Hock-Chai@xxxxxxxxxxxxxxx>]

Thanks Scott.  

- I've a socket program that is able to connect and logon to its main
menu.  ==> I don't think  firewall is the problem.

- No clue on how proxy program work :( (Will check into though).

- It does sounds bad to tell user that AS400 can't telnet to it but DOS
can.  

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Scott Klement
Sent: Tuesday, April 11, 2006 2:34 PM
To: Midrange Systems Technical Discussion
Subject: RE: telnet


Lim,

The issue is that the TELNET command on the iSeries tries to negotiate a
few settings with the system it's connected to. In particular, it wants
to know if it can use it's own 5250 protocol or if it has to use a
foreign terminal type like VT100, or an NVT, etc.

This isn't an issue with the Windows telnet client because it doesn't
speak 5250, and it goes into VT100 mode without trying to negotiate
anything :)

The iSeries TELNET client keeps trying to negotiate the terminal type
until it receives an appropriate response from the server, or until it
receives some human-readable data.  If it receives the data, it'll
assume whichever terminal type you specified for the ASCOPRMOD()
parameter, but I don't think it's ever getting that far.

The solution is to have the paging server send some text to be
displayed, that'll tell the iSeries TELNET client to give up on it's
negotiations. 
If that's not an option, then I suggest writing a proxy program that you
can connect to via your TELNET client.  The proxy can send the
appropriate codes to cancel the terminal negotiation.

Aside from problems negotiating the terminal settings, the other
possible problem would be that a firewall is blocking the port.  If
that's what's happening, you'd eventually (probably in about 120 secs)
get an error message that says "No response from remote host system
within open time-out.".  Since you didn't report that symptom, I'm
assuming that it's not a firewall issue.

Folks, if you want to see the type of problem Lim is having, it should
be easy to reproduce by trying to connect to an HTTP server with the
iSeries telnet client.  For example, if you're running an HTTP server on
the iSeries, you could type:

      TELNET RMTSYS(LOCALHOST) PORT(80)

---
Scott Klement  http://www.scottklement.com

On Tue, 11 Apr 2006, Lim Hock-Chai wrote:

> Just tried it and get the same result.
> TELNET RMTSYS('147.187.223.13') ASCOPRMOD(*VT100) PORT(2001) TELNET 
> RMTSYS('147.187.223.13') ASCOPRMOD(*VT52) PORT(2001)
>
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