Re: SFTP SSH Client Issues

[Allan Staller]

In this case the SSH-Client is you. (You are initiating the connection). The 
remote site is the server.
I was just trying to give you a starting point for the search.
Rereading the OP, another thing to look at is the MTU size. (see the TCPIP 
books). There is a parameter PATHMTUDISCOVERY(?) that might help.

Is your SSH task being dispatched frequently enough?
Any "artificial" timeouts in place?  (firewall,..)
Traceroute can be used as a non-intrusive method of finding any network "choke 
points"; bad routing and once the connections leaves your site.

The packet trace and IBM's analysis pretty much sums it up. You need to get 
past the packet loss issue. The trick is finding out what is causing the packet 
loss.

Good luck,


-Original Message-
From: IBM Mainframe Discussion List  On Behalf Of 
Dazzo, Matt
Sent: Tuesday, July 2, 2019 12:46 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: SFTP SSH Client Issues

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  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  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 affi

Re: SFTP SSH Client Issues

[Dazzo, Matt]

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  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  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 subscr

Re: SFTP SSH Client Issues

[Allan Staller]

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  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

SFTP SSH Client Issues

[Dazzo, Matt]

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

Re: SSH Client

[Shmuel Metz (Seymour J.)]

In
,
on 10/09/2015
   at 01:10 PM, Mark Pace  said:

>I can start typing a command and press tab and it will autocomplete a
>file name or command.

That's a function of the shell that you're using.
 
-- 
 Shmuel (Seymour J.) Metz, SysProg and JOAT
 ISO position; see  
We don't care. We don't have to care, we're Congress.
(S877: The Shut up and Eat Your spam act of 2003)

--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN

Re: SSH Client

[Mark Pace]

Thank you all!

On Fri, Oct 9, 2015 at 1:39 PM, John McKown 
wrote:

> On Fri, Oct 9, 2015 at 12:10 PM, Mark Pace  wrote:
>
> > When I logon to a linux system
> > I can start typing a command and press tab and it will autocomplete a
> file
> > name or command.
> > If I press up arrow it will recall previous commands.
> >
> > I can't figure out how to do this in Unix System Services using SSH.
> > Is this a daemon setup, client setup?  I've gone through z/OS OpenSSH
> > User's Guide and I don't see anything that looks like what I am looking
> > for.
> >
> >
> The history and editing commands are implemented in BASH using an
> integrated version of "GNU Readline". The tab completion for commands or
> file selection is a part of BASH itself. My suggestion is to run BASH on
> z/OS. It is available on the CBTTape (http://www.cbttape.org/cbtdowns.htm
> ),
> file 918 is the executable only. File 919 contains both the executable and
> ported source.
> You can also get the ported source from :
> https://github.com/JohnArchieMckown/bash
> or the executables, in a z/OS PAX file, via
>
> https://github.com/JohnArchieMckown/bash/blob/bash-4.2-zos/bash-executable.pax.Z
> As you may have guessed, I am the one who did this port. This is BASH 4.2
> patch level 53. This has the "shell shock" fix installed. You can also
> request an alternate port from RocketSoftware:
> http://www.rocketsoftware.com/ported-tools/bash-4254
> ​This latter port seems to be one patch level higher than mine.​
>
>
> --
>
> Schrodinger's backup: The condition of any backup is unknown until a
> restore is attempted.
>
> Yoda of Borg, we are. Futile, resistance is, yes. Assimilated, you will be.
>
> He's about as useful as a wax frying pan.
>
> 10 to the 12th power microphones = 1 Megaphone
>
> Maranatha! <><
> John McKown
>
> --
> For IBM-MAIN subscribe / signoff / archive access instructions,
> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
>



-- 
The postings on this site are my own and don’t necessarily represent
Mainline’s positions or opinions

Mark D Pace
Senior Systems Engineer
Mainline Information Systems

--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN

Re: SSH Client

[John McKown]

On Fri, Oct 9, 2015 at 12:10 PM, Mark Pace  wrote:

> When I logon to a linux system
> I can start typing a command and press tab and it will autocomplete a file
> name or command.
> If I press up arrow it will recall previous commands.
>
> I can't figure out how to do this in Unix System Services using SSH.
> Is this a daemon setup, client setup?  I've gone through z/OS OpenSSH
> User's Guide and I don't see anything that looks like what I am looking
> for.
>
>
The history and editing commands are implemented in BASH using an
integrated version of "GNU Readline". The tab completion for commands or
file selection is a part of BASH itself. My suggestion is to run BASH on
z/OS. It is available on the CBTTape (http://www.cbttape.org/cbtdowns.htm),
file 918 is the executable only. File 919 contains both the executable and
ported source.
You can also get the ported source from :
https://github.com/JohnArchieMckown/bash
or the executables, in a z/OS PAX file, via
https://github.com/JohnArchieMckown/bash/blob/bash-4.2-zos/bash-executable.pax.Z
As you may have guessed, I am the one who did this port. This is BASH 4.2
patch level 53. This has the "shell shock" fix installed. You can also
request an alternate port from RocketSoftware:
http://www.rocketsoftware.com/ported-tools/bash-4254
​This latter port seems to be one patch level higher than mine.​


-- 

Schrodinger's backup: The condition of any backup is unknown until a
restore is attempted.

Yoda of Borg, we are. Futile, resistance is, yes. Assimilated, you will be.

He's about as useful as a wax frying pan.

10 to the 12th power microphones = 1 Megaphone

Maranatha! <><
John McKown

--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN

Re: SSH Client

[Michael Knigge]

Mark,

this is a feature of the Shell. Linux uses (mostly) the BASH as default 
Shell. The z/OS USS uses an other shell, but as far as I know there is a 
port: See http://www-03.ibm.com/systems/z/os/zos/features/unix/bpxa1ty1.html




Bye,
Michael


Am 09.10.2015 um 19:10 schrieb Mark Pace:

When I logon to a linux system
I can start typing a command and press tab and it will autocomplete a file
name or command.
If I press up arrow it will recall previous commands.

I can't figure out how to do this in Unix System Services using SSH.
Is this a daemon setup, client setup?  I've gone through z/OS OpenSSH
User's Guide and I don't see anything that looks like what I am looking for.



--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN

Re: SSH Client

[Lester, Bob]

Hi Folks,

 Sounds like a bash shell to me...

BobL

-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf 
Of Mark Jacobs - Listserv
Sent: Friday, October 09, 2015 11:21 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: SSH Client [ EXTERNAL ]

I think it's the function of the shell. My OMVS segment specifies /bin/tcsh 
which I find has more functionally that /bin/sh (which is the default shell).

Mark Jacobs

> Mark Pace <mailto:pacemainl...@gmail.com> October 9, 2015 at 1:10 PM 
> When I logon to a linux system I can start typing a command and press 
> tab and it will autocomplete a file name or command.
> If I press up arrow it will recall previous commands.
>
> I can't figure out how to do this in Unix System Services using SSH.
> Is this a daemon setup, client setup? I've gone through z/OS OpenSSH 
> User's Guide and I don't see anything that looks like what I am 
> looking for.
>
> --
> The postings on this site are my own and don’t necessarily represent 
> Mainline’s positions or opinions
>
> Mark D Pace
> Senior Systems Engineer
> Mainline Information Systems
>
> --
> For IBM-MAIN subscribe / signoff / archive access instructions, send 
> email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
>
>
> Please be alert for any emails that may ask you for login information 
> or directs you to login via a link. If you believe this message is a 
> phish or aren't sure whether this message is trustworthy, please send 
> the original message as an attachment to 'phish...@timeinc.com'.
>

--
For IBM-MAIN subscribe / signoff / archive access instructions, send email to 
lists...@listserv.ua.edu with the message: INFO IBM-MAIN

This e-mail transmission may contain information that is proprietary, 
privileged and/or confidential and is intended exclusively for the person(s) to 
whom it is addressed. Any use, copying, retention or disclosure by any person 
other than the intended recipient or the intended recipient's designees is 
strictly prohibited. If you are not the intended recipient or their designee, 
please notify the sender immediately by return e-mail and delete all copies. 
OppenheimerFunds may, at its sole discretion, monitor, review, retain and/or 
disclose the content of all email communications.


--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN

Re: SSH Client

[Mark Jacobs - Listserv]

I think it's the function of the shell. My OMVS segment specifies 
/bin/tcsh which I find has more functionally that /bin/sh (which is the 
default shell).


Mark Jacobs


Mark Pace 
October 9, 2015 at 1:10 PM
When I logon to a linux system
I can start typing a command and press tab and it will autocomplete a file
name or command.
If I press up arrow it will recall previous commands.

I can't figure out how to do this in Unix System Services using SSH.
Is this a daemon setup, client setup? I've gone through z/OS OpenSSH
User's Guide and I don't see anything that looks like what I am 
looking for.


--
The postings on this site are my own and don’t necessarily represent
Mainline’s positions or opinions

Mark D Pace
Senior Systems Engineer
Mainline Information Systems

--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN


Please be alert for any emails that may ask you for login information 
or directs you to login via a link. If you believe this message is a 
phish or aren't sure whether this message is trustworthy, please send 
the original message as an attachment to 'phish...@timeinc.com'.




--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN

SSH Client

[Mark Pace]

When I logon to a linux system
I can start typing a command and press tab and it will autocomplete a file
name or command.
If I press up arrow it will recall previous commands.

I can't figure out how to do this in Unix System Services using SSH.
Is this a daemon setup, client setup?  I've gone through z/OS OpenSSH
User's Guide and I don't see anything that looks like what I am looking for.

-- 
The postings on this site are my own and don’t necessarily represent
Mainline’s positions or opinions

Mark D Pace
Senior Systems Engineer
Mainline Information Systems

--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN