Putty server unexpectedly closed network connection - putty

I'm getting this error when using Putty:
Server unexpectedly closed network connection
I think there is a problem with the network in my office because all computers at my work workplace have the same problem. How can I fix this?

If this error happens after a while that you are connected to the host, probably in your work network have some router periodically closing the connections, a workaround for this is keep your terminal busy, running something like top when you are away, but remember this creates a security breach.
Basically your connection is being closed by inactivity, if you just keep something running in your terminal, is more likely that it doesn't close the connection, I mean by something running as the terminal screen being refreshed constantly, if you run a Linux box, type the command top, that shows the box load and refreshes every 5 seconds.

Related

SSH connections from windows are aborted within a minute

If I start an SSH connection with my windows 10 laptop, it gets aborted within a minute. Even when I'm actively using the connection.
I tried multiple servers (Ubuntu 18, 16 and ESXi 6.7) all with the same problem, also tried to use different clients (putty and mobaXterm).
Did a packet capture and it does look like the connected server sends a RST with ACK to my laptop. After which my laptop responds FIN with ACK.
If I setup the same connection from my phone with JuiceSSH it keeps working normally. That's why I suspect my laptop, but I have no idea how to resolve it.
Any ideas?
In putty feel free to try with:
In your session properties, go to Connection and under Sending of null packets
to keep session active, set Seconds between keepalives (0 to turn off) to e.g.
300 (5 minutes).
source: https://patrickmn.com/aside/how-to-keep-alive-ssh-sessions/

Perforce - RpcTransport: partial message read

When using "revert -a" through P4V it waits for a few minutes and throws this error back at me.
RpcTransport: partial message read
TCP receive failed.
read: socket: WSAECONNRESET
The server status returns fine and there are no locked database files.
I suspect this problem is local to this computer as others don't have the same issue. Issueing the same command through the command prompt just has the command prompt sit there indefinitly.
Other commands such as submit and add will have the visual client sit there indefinitely but does not throw and error.
The files are stored on a local drive. This happens with multiply depots/workstations.
The 'WSAECONNRESET' error is issued by Windows, when a network socket is forcibly closed.
Regular occurrences of this error can indicate network problems.
More information is available here:
http://answers.perforce.com/articles/KB/2968/
Hope this helps,
Jen!
I got the same on windows machine. I guess in my case it was caused by corrupted config settings and because of popup error message I had no chance to set it correctly via GUI.
The command line SET command helped to set port and host name again:
p4 set P4PORT=<portnum>
This command reenables the GUI config dialog
A few years late, but for those still facing this:
I faced this error when fetching files from a large repo. I believe what caused this for me was low internet upload speeds due to which - even though I had high a download speed - the TCP acknowledgment from my computer was not getting sent, causing a connection failure.
Perform an upload speed test to determine if it is very low (in my case it had dropped to less than 0.1 Mbps). Fixing upload speeds is a separate topic, but in case it helps try restarting your router as a first step.

Stale connection with Pheanstalk

I'm using beanstalkd to offload some work to other machines. The setup is a bit unusual, the server is on the internet (public ip) but the consumers are behind adsl lines on some peoples homes. So there is a linux server as client going out through a dynamic ip and connecting to the server to get a job. It's all PHP and I'm using pheanstalk library.
Everything runs smoothly for some time, but then the adsl changes the IP (every 24h hours the provider forces a disconnect-reconnect) the client just hangs, never to go out of "reserve".
I thought that putting a timeout on the reserve would help it, but it didn't. As it seems, the client issues a command and blocks, it never checks the timeout. It just issues a reserve-with-timeout (instead of a simple reserve) and it is the servers responsibility to return a TIME_OUT as the timeout occurs. The problem is, the connection is broken (but the TCP/IP doesn't know about that yet until any of the sides try to talk to the other side) and if the client blocked reading, it will never return.
The library seems to have support for some kind of timeouts locally (for example when trying to connect to server), but it does not seem to contemplate this scenario.
How could I detect the stale connection and force a reconnect? Is there some kind of keepalive on the protocol (and on the pheanstalk itself)?
Thanks!
You could try to close each connection right after the request is answered and reopen a new connection each time.
There is no close() function but you deleting the Pheanstaly Object with unset($pheanstalk) will close it.
This explanation is quite helpful:
Pheanstalk (PHP client for beanstalk) - how do connections work?
I haven't tried it yet, but I came up with the idea of connecting to the beanstalk server through an SSH tunnel. We can enable the ServerAliveCountMax and ServerAliveInterval options on the tunnel, so that a network or server failure will cause the tunnel to close. This should then cause the pheanstalk client to report an error.

Irregular socket errors (10054) on Windows application

I am working on a Windows (Microsoft Visual C++ 2005) application that uses several processes
running on different hosts in an intranet.
Processes communicate with each other using TCP/IP. Different processes can be on the
same host or on different hosts (i.e. the communication can be both within the same
host or between different hosts).
We have currently a bug that appears irregularly. The communication seems to work
for a while, then it stops working. Then it works again for some time.
When the communication does not work, we get an error (apparently while a process
was trying to send data). The call looks like this:
send(socket, (char *) data, (int) data_size, 0);
By inspecting the error code we get from
WSAGetLastError()
we see that it is an error 10054. Here is what I found in the Microsoft documentation
(see here):
WSAECONNRESET
10054
Connection reset by peer.
An existing connection was forcibly closed by the remote host. This normally
results if the peer application on the remote host is suddenly stopped, the
host is rebooted, the host or remote network interface is disabled, or the
remote host uses a hard close (see setsockopt for more information on the
SO_LINGER option on the remote socket). This error may also result if a
connection was broken due to keep-alive activity detecting a failure while
one or more operations are in progress. Operations that were in progress
fail with WSAENETRESET. Subsequent operations fail with WSAECONNRESET.
So, as far as I understand, the connection was interrupted by the receiving process.
In some cases this error is (AFAIK) correct: one process has terminated and
is therefore not reachable. In other cases both the sender and receiver are running
and logging activity, but they cannot communicate due to the above error (the error
is reported in the logs).
My questions.
What does the SO_LINGER option mean?
What is a keep-alive activity and how can it break a connection?
How is it possible to avoid this problem or recover from it?
Regarding the last question. The first solution we tried (actually, it is rather a
workaround) was resending the message when the error occurs. Unfortunately, the
same error occurs over and over again for a while (a few minutes). So this is not
a solution.
At the moment we do not understand if we have a software problem or a configuration
issue: maybe we should check something in the windows registry?
One hypothesis was that the OS runs out of ephemeral ports (in case connections are
closed but ports are not released because of TcpTimedWaitDelay), but by analyzing
this issue we think that there should be plenty of them: the problem occurs even
if messages are not sent too frequently between processes. However, we still are not
100% sure that we can exclude this: can ephemeral ports get lost in some way (???)
Another detail that might help is that sending and receiving occurs in each process
concurrently in separate threads: are there any shared data structures in the
TCP/IP libraries that might get corrupted?
What is also very strange is that the problem occurs irregularly: communication works
OK for a few minutes, then it does not work for a few minutes, then it works again.
Thank you for any ideas and suggestions.
EDIT
Thanks for the hints confirming that the only possible explanation was a connection closed error. By further analysis of the problem, we found out that the server-side process of the connection had crashed / had been terminated and had been restarted. So there was a new server process running and listening on the correct port, but the client had not detected this and was still trying to use the old connection. We now have a mechanism to detect such situations and reset the connection on the client side.
That error means that the connection was closed by the
remote site. So you cannot do anything on your programm except to accept that the connection is broken.
I was facing this problem for some days recently and found out that Adobe Acrobat Reader update was the culprit. As soon as you completely uninstall Adobe from the system everything returns back to normal.
I spent a long time debugging a 10054/10053 error in s3 pre-signed uploads
Turns out that the s3 server will reject pre-signed s3 uploads for the first 15 minutes of it's life.
So - If you're debugging s3 check it's not a new bucket.
If you're debugging something else - this is most likely a problem on the server side not client side.

FSMountServerVolumeSync showing unwanted dialog when connection fails, how to remove?

I am using FSMountServerVolumeSync to mount an afp share. All works fine, unless the connection to the server does not work. I wrote code to handle this gracefully and retry later (this is for a background process). However each time the connection fails I get this nasty popup from MacOSX :
"There was a problem connecting to the server ....."
This is very annoying. Is there a way to avoid this popup?

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