Is it possible to use Windows Telnet to connect to IBM i?

[LiQuiD_FuSioN]

This may sound silly, but is it possible to use the Telnet client from a Windows command line session to connect to an AS400 system?

I heard that it's possible and you'll be greeted with a very minimal green screen sign on. However, when I try it myself I get a blank screen and it eventually closes out. Using Telnet straight from AS400 to another remote AS400 gives the message, "TELNET session ended. Connection closed."

I've already checked through IBM's set of instructions:

https://www.ibm.com/support/knowledgecenter/ssw_i5_54/rzaiw/rzaiwdetprobtelnet.htm

Any tips would be appreciated. Thanks!

[Scott Klement]

Re: Is it pssible to use Windows Telnet to connect to AS400?

yes, using Windows Telnet works fine for most things. The keyboard mapping will not be right and you'll have to do some weird things there... but otherwise it works fine.

Based on the problems you're mentioning, something isn't set up right. (You're having the same problem from the IBM Telnet client as well, so it's not a problem with the Windows one.) Possibly there's a firewall that's blocking access to your IBM i Telnet server? Or possibly the Telnet server hasn't been started? Or maybe it's configured to only allow SSL/TLS encrypted sessions? Or maybe there's a network problem?

These are some of the most likely scenarios, anyway. Someone on your side needs to troubleshoot things and see what is wrong.

[LiQuiD_FuSioN]

Re: Is it pssible to use Windows Telnet to connect to AS400?

yes, using Windows Telnet works fine for most things. The keyboard mapping will not be right and you'll have to do some weird things there... but otherwise it works fine.

Based on the problems you're mentioning, something isn't set up right. (You're having the same problem from the IBM Telnet client as well, so it's not a problem with the Windows one.) Possibly there's a firewall that's blocking access to your IBM i Telnet server? Or possibly the Telnet server hasn't been started? Or maybe it's configured to only allow SSL/TLS encrypted sessions? Or maybe there's a network problem?

These are some of the most likely scenarios, anyway. Someone on your side needs to troubleshoot things and see what is wrong.

Thanks for taking time to respond, Scott.

Telnet is started when I look at iNav, and it requires secure connections, yes. When I fire up Telnet I do indicate to use port 992. Can ping loopback on both machines, 5250 sessions work fine. Might be some kind of Firewall/network problem perhaps then as you mention.

[LiQuiD_FuSioN]

Re: Is it pssible to use Windows Telnet to connect to AS400?

Actually according to this IBM Rebook:
If you have never allowed automatic configuration of virtual devices on your server, the Devices System
Value Maximum number of devices value is 0. A Telnet connection attempt will fail when the number of
devices in use exceeds the Maximum number of devices. A device in use has the status ACTIVE or
SIGNON DISPLAY. If you try to signon, you receive a message (TCP2504) indicating that the Telnet client
session has ended and the connection is closed.

https://publib.boulder.ibm.com/iseries/v5r1/ic2924/info/rzaiw/rzaiw.pdf

I'm curious, is it possible to use some kind of Telnet parameter to indicate what workstation ID/device description to use when connecting? Because we don't allow automatic dev config.

[Scott Klement]

Re: Is it pssible to use Windows Telnet to connect to AS400?

First of all, I wanted to point out that port 992 is SSL Telnet (not 'normal' Telnet) so you'll need to use a telnet client that's capable of SSL. (Unless you're doing something weird like running unencrypted telnet on 992 despite that 992 is standard for SSL telnet. That would be very weird.)

Second... the Telnet protocol does provide the ability to pass arbitrary variables between the client and server, and IBM i will use certain ones to determine the device name. Therefore, it's possible to specify a device name, but ONLY if the client program supports it. (Windows Telnet does not.)

Another way is to use a Telnet Device Initialization Exit program. A program like that can assign device names using any logic you want.

[DeadManWalks]

Re: Is it pssible to use Windows Telnet to connect to AS400?

Why are you tring to do it this way? If you want a free way you can get the ibm i access client solutions.

[LiQuiD_FuSioN]

Re: Is it pssible to use Windows Telnet to connect to AS400?

First of all, I wanted to point out that port 992 is SSL Telnet (not 'normal' Telnet) so you'll need to use a telnet client that's capable of SSL. (Unless you're doing something weird like running unencrypted telnet on 992 despite that 992 is standard for SSL telnet. That would be very weird.)

Second... the Telnet protocol does provide the ability to pass arbitrary variables between the client and server, and IBM i will use certain ones to determine the device name. Therefore, it's possible to specify a device name, but ONLY if the client program supports it. (Windows Telnet does not.)

Another way is to use a Telnet Device Initialization Exit program. A program like that can assign device names using any logic you want.

That's what I thought. The Windows Telnet client (which you have to install manually in Windows by adding the feature in) is very limited.

It is not something I wanted to actually use but it was interesting to at least try it out for learning purposes. One of our external people was trying to do it and we had to tell them no, that we do not use insecure regular telnet anymore.

Yes, we are looking into the free ACS product by IBM, which uses Java. For now we all use the iSeries 5250 client.

I appreciate your responses! It was an odd thread really.

[jtaylor___]

Re: Is it pssible to use Windows Telnet to connect to AS400?

FYI, iACS 5250 is not free.

...IBM i Access Client Solutions uses the same IBM i host servers as the other IBM i Access Family products and requires the same IBM i Access Family license (XW1) in order to use the 5250 emulation and Data Transfer features.
...

http://www-03.ibm.com/systems/power/software/i/access/solutions.html

[Viking]

Re: Is it pssible to use Windows Telnet to connect to AS400?

I believe it's included if you're current on IBM software maintenance.

[Scott Klement]

Re: Is it pssible to use Windows Telnet to connect to AS400?

The Windows Telnet does work... Not if you only support SSL, of course... For us, we allow anyone using our VPN whether using SSL or not (since the VPN protects it) so we can use Windows Telnet. Looks like this:




As you can see, it has no color, it is missing underlines... and less obvious is that the keyboard mapping isn't great. But it does basically work.

If you want a free 5250 client, you can try this one (java)

http://tn5250j.sourceforge.net/

Or this one (Windows .EXE file):

http://tn5250.sourceforge.net/

These do not require XW1 or any other special licensed program, just the telnet server and they provide a full 5250 client. They don't have all the other features that IBM's ACS has, though (not as many configurable options, no file upload/download tool, no SQL script tool, can't be used as a system console, etc.) But they're pretty good. I am one of the authors of the 2nd one, and at my previous job we used it throughout the company for all PCs. It's not as nice as client access for sure, but for the average joe in our shop, it worked fine.

It does have the advantage that you can use it from the command line (much like the Windows Telnet) if you have it added to your PATH you can do stuff like this:

tn5250 env.DEVNAME=DSP10 ssl:power8.profoundlogic.local

That command line will connect to a server named power8.profoundlogic.local using SSL and will try to use device named DSP10. So it has command-line capabilities and supports SSL and device naming which Windows Telnet does not. The Java one (tn5250j) has more features than the exe one, and is cross-platform... but I dont have much personal experience with it, so you'd have to learn it from the docs :-)

Good luck

[tomliotta]

Re: Is it pssible to use Windows Telnet to connect to AS400?

I believe it's included if you're current on IBM software maintenance.

Since systems generally have no clue whether you're current on maintenance or not, the maintenance status would seem unlikely. AFAIK, the basic iACS is "free"; but the telnet client and file transfer components require additional licensing that comes at a cost. It's effectively the same as it was with previous versions of the functions.

From IBM i Access Client Solutions Overview (emphasis added):

IBM i Access Client Solutions uses the same IBM i host servers as the other IBM i Access Family products and requires the same IBM i Access Family license (XW1) in order to use the 5250 emulation and Data Transfer features.

[jtaylor___]

Re: Is it pssible to use Windows Telnet to connect to AS400?

I believe it's included if you're current on IBM software maintenance.

It's included if you have a license for IBM i Access.

[tomliotta]

Re: Is it pssible to use Windows Telnet to connect to AS400?

It's included if you have a license for IBM i Access.

And even if there is no maintenance (e.g., for a V5R3 system today), the license can continue to work. There is a cost for the license separate from maintenance.