1747987 Members
4792 Online
108756 Solutions
New Discussion юеВ

Re: SSH Users Dropped

 
Steve Calnek
Advisor

SSH Users Dropped

Hi,

I have an Alpha Server DS10 running OVMS 8.3 with TCPIP Services 5.6-ECO2.

We use SSH to allow PC terminal connections to the server in a secure LAN.

On a regular day I'll have 3 to 8 users, different one's on different days, tell me that they were dropped in the middle of data entry. They can log back in right away.

I've verified that its during data entry and not idle timeouts.

I've tried several different emulator programs and the results are the same. The network is not anywhere close to capacity, all PC are new(ish). There are maybe 35 users logged in at anyone time.

The SSH documentation really offers nothing and what log files there are don't show anything.

Any ideas, all are welcome.

Thanks.

Steve.
19 REPLIES 19
Steven Schweda
Honored Contributor

Re: SSH Users Dropped

Are users of other services (rsh, Telnet)
similarly affected? Any reason not to
suspect some generic network (hardware,
firewall, ...) problem?

Run a continuous "ping" to a problem client
system, and record the results to compare
with failure complaints?
Steve Calnek
Advisor

Re: SSH Users Dropped

My first thought had been a firewall problem but I'm assured by the network manager that thats not it.

There are no telnet sessions on this LAN but prior to upgrading to 8.3 of OVMS we used and open source port of an SSH1 server that I think was done by David Jones. We never had any problems with these random drops. This is new since we upgraded a month ago.

There are a lot of other network services that would be effected if it was server hardware and I've not seen anything in there logs to indicate a problem.

I will try the continuous ping. Thanks for the idea.

Steve/
Volker Halle
Honored Contributor

Re: SSH Users Dropped

Steve,

does the OpenVMS accounting file (process or image accounting records) show any specific error status if the user is dropped ? If so, you could obtain exact date and time data about the dropped connections.

Volker.
Wim Van den Wyngaert
Honored Contributor

Re: SSH Users Dropped

There is a server config item called IdleTimeOut. Is it active ?

Wim
Wim
Volker Halle
Honored Contributor

Re: SSH Users Dropped

Steve,

after logging into our Alpha via TELNET, then using SSH to login to our rx2600 and then killing the TELNET-connection, the interactive process on the rx2600 is (according to accounting) terminated with:

Final status code: 0001C0F4
Final status text: %RMS-F-RER, file read error

If I log out normally on the rx2600 and thus normally terminate the SSH connection, the final status code is 10000001 %SYSTEM-S-NORMAL, normal successful completion

So you may indeed try to check your accounting file with:

$ ACC/SINCE=/STATUS=0001C0F4/PROCESS=INTERACTIVE

to see if this shows any pattern or shows more SSH users getting dropped without complaining.

Volker.
Steve Calnek
Advisor

Re: SSH Users Dropped

Gentlemen!

Thanks for the great suggestion's. I'll look into this today and report back shortly.

Steve/
Kees L.
Advisor

Re: SSH Users Dropped

Hello Steve,

In our system in SYS$SYSDEVICE:[TCPIP$SSH.SSH2]SSHD2_CONFIG.; we have the entry IdleTimeOut 8h.
Should only logout after idle time, but I have had times where I was logged off after having been typing in the windows minutes earlier. So I fear IdleTimeOut doesn't in all cases only work after being idle. Try change the value to see if it makes any difference.
Steve Calnek
Advisor

Re: SSH Users Dropped

Using the suggestions to date I've try setting idle timeout with out effect and i've used Volkers command to review the logs in detail. The error you found is not what is happening here but I have found a consistent error.
NorthVancouver >acc/since=today/type=process/process=interactive/user=dsutherland/full

INTERACTIVE Process Termination
-------------------------------
Username: DSUTHERLAND UIC: [GRUSSELL]
Account: Finish time: 11-APR-2008 10:04:28.28
Process ID: 0000145C Start time: 11-APR-2008 09:04:27.25
Owner ID: Elapsed time: 0 01:00:01.03
Terminal name: FTA26: Processor time: 0 00:00:00.36
Remote node addr: Priority: 4
Remote node name: Privilege <31-00>: 00108000
Remote ID: DSUTHERLAND(LOC Privilege <63-32>: 00000000
Remote full name: 192.168.0.63
Posix UID: -2 Posix GID: -2 (%XFFFFFFFE)
Queue entry: Final status code: 00002BD4
Queue name:
Job name:
Final status text: %SYSTEM-F-EXITFORCED, forced exit of image or process by SYS$DELPRC
Page faults: 1053 Direct IO: 249
Page fault reads: 106 Buffered IO: 1027
Peak working set: 7504 Volumes mounted: 0
Peak page file: 176064 Images executed: 7


NorthVancouver >help/message "%SYSTEM-F-EXITFORCED"


EXITFORCED, forced exit of image or process by SYS$DELPRC

Facility: SYSTEM, System Services

Explanation: Another process caused the image to exit using the SYS$DELPRC
system service. In this use of SYS$DELPRC, an image exit
occurs (rather than a process deletion).

User Action: None. This is a fatal error message.

Any suggestions as to what could cause this?

Thanks

Steve/
Richard Whalen
Honored Contributor

Re: SSH Users Dropped

does the system have an idle process killer?