Thanks Allan, I learned that there actually several sftp servers behind 1 or more load balancers. So maybe there is something going on with the connection that the open ssh client cannot handle?
Do you or any else know of any other sftp client software either free or commercial we can look at? All involved think it's the open ssh client because it's the only one having the problem, well that we know of. Thanks Matt -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Allan Staller Sent: Tuesday, July 02, 2019 8:55 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: SFTP SSH Client Issues Check the service your SSH client is receiving. If I understand the reported symptoms, you can get this behavior if z/OS does not dispatch the SSH Client. Many of the same items vis-à-vis (network and FTP) also apply to SSH. Routing? Class of Service? What is happening at time of observed issues. Excessive remote activity, excessive local activity? Run a traceroute to the remote site. See if there are any major lags in the path. HTH, -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Dazzo, Matt Sent: Tuesday, July 2, 2019 7:45 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: SFTP SSH Client Issues We are running zos 2.2 with cozbatch 5.5.0 to initiate ssh sftp client session to a linux server over the internet. We get the error 'Received disconnect from xxx.0.xx.xxx: 11: Sending of channel data timed out' at peak times on the server through the day, this is not our server. I have run a tcp packet trace and sent it off to IBM, I have that response below but they are saying there are retransmissions on the connection that the client is not handling. The server folks tell me they have no other clients that have problems. Here is the catch, it only happens with the ssh client. I can pull over 200 files using filezilla on my desktop and same for my RH linux guest on zvm. I'm at a loss as to where to go with this issue, wonder if anyone else has ever had this issue or might have suggestions to try? Thanks Matt Current job settings -oConnectTimeout=600" -oServerAliveInterval=600" -oTCPKeepAlive=yes" -oServerAliveCountMax=5" IBM Response to trace info - There is a significant level of packet loss between these systems, which is forcing retransmission of packets. Your local network support team will need to investigate that. - The server system is very sluggish in performing the retransmissions. There are long periods where it is not sending the missing data, which is likely why the server's administrators are saying that the client is not responding (it can't respond at the application layer until the missing data arrives). One example I examined, it was 9 seconds before the retransmission occurred, for another (closer to the end) it was 79 seconds. That is way beyond normal! That system's administrators need to contact the TCP software's vendor to get this corrected. Thanks, ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ::DISCLAIMER:: -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. E-mail transmission is not guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or may contain viruses in transmission. The e mail and its contents (with or without referred errors) shall therefore not attach any liability on the originator or HCL or its affiliates. Views or opinions, if any, presented in this email are solely those of the author and may not necessarily reflect the views or opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of authorized representative of HCL is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any email and/or attachments, please check them for viruses and other defects. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
