Are all ports really open? Can you open a connection going the other way? Are the hanging servers trying to do a reverse dns lookup on the windows workstation? You could use the network tracing facilities on z/VM to get more insight in to what is happening.
-----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 11:43 AM To: IBMVM@LISTSERV.UARK.EDU Subject: FTP Problem First, a diagram. Windows Server |-- 10.199.8.15 | Windows | Workstation | z/VM 5.3 10.200.70.35 ------ Firewall ------ 10.199.103.48 | | | Windows laptop |-- 10.199.16.x We are attempting to FTP from the Windows PC at 10.200.70.35 to the three addresses on the 10.199 network. Our network guy says that the three 10.199 addresses have been fully opened on the firewall for 10.200.70.35 to access. That is, all ports are available. - 10.200.70.35 can FTP to 10.199.16.x, the network guy's laptop. - When 10.200.70.35 attempts to FTP to either 10.199.8.15 or 10.199.103.48, the FTP hangs at userid and password validation for several minutes before dying. - Several people have confirmed that the userid and password are correct. - The Windows Server at 10.199.8.15 is tightly access controlled. - z/VM at 10.199.103.48 does not restrict FTP access by IP address, just userid and password. - z/VM can FTP to 10.199.8.15. - Various servers and workstations can FTP to z/VM. - Pings are blocked by the firewall, but a TRACERTE from z/VM seems to show 10.200.70.35 can be reached, just no TTL information. Our network guy is really busy at the moment, so I'm wondering if there is anything I can look at on z/VM that would show why the FTP logon is hanging/failing. 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.
