Also look at chapters 7, 8 and 9 in the z/VM TCP/IP Diagnosis Guide version 5 release 3, which will show you how to do packet trace and format the results, and also FTP server traces. If you see the VM FTP server try to open a connection back to the windows box on a different port, and you never get a response, that would be a big clue. You can also get IBM support to help you read those traces. They love to do stuff like that.
-----Original Message----- From: The IBM z/VM Operating System [mailto:IBMVM@LISTSERV.UARK.EDU] On Behalf Of peter.w...@ttc.ca Sent: Friday, April 08, 2011 2:03 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: FTP Problem Thanks for the responses. >Are all ports really open? I think so. I trust the network guy, and he showed me the firewall settings (which didn't mean a lot to me). >Can you open a connection going the other way? I can do a trace route which appears to work. Access to 10.200.70.35 is difficult. See below. >Are the hanging servers trying to do a reverse dns lookup on the >windows workstation? Possibly. I don't know how to tell. >Is the windows machine connecting to z/VM using command line or a GUI? GUI. >Try the dos prompt command line ftp and see if it still fails. I tried when I visited in December. No luck. One difficulty is that 10.200.70.35 is located at another facility in a high security area with very restricted access, and visitors are subject to being booted out immediately if 'something' happens. This includes my contact at the other facility. That's why I want to try and work the problem from the z/VM end. >Did they check firewall configuration on the Windows boxes? The default >settings for the Windows firewalls don't permit FTP. The workstation 10.200.70.35 can successfully FTP out, and the server 10.199.8.15 accepts FTP connections to it, so I don't think that the Windows firewall is the problem. Peter The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review retransmission dissemination or other use of or taking any action in reliance upon this information by persons or entities other than the intended recipient or delegate is strictly prohibited. If you received this in error please contact the sender and delete the material from any computer. The integrity and security of this message cannot be guaranteed on the Internet. The sender accepts no liability for the content of this e-mail or for the consequences of any actions taken on the basis of information provided. The recipient should check this e-mail and any attachments for the presence of viruses. The sender accepts no liability for any damage caused by any virus transmitted by this e-mail. This disclaimer is property of the TTC and must not be altered or circumvented in any manner.
