Frequent SSH disconnections, need to verify the SS (General questions)

Hi,
Currently we are facing frequent disconnections from WodTunnel. Our application is trying to reconnect, but connection persists for some time. Now are clients, who are using the application 24x7 are also increasing. We want to verify the SSH servers that we had placed at our data center for the following things.

1> Is the SSH server configuration is proper as required for the SSH software to work.
2> If we want to put virtual servers, then what will be the combination of virtual and physical servers for the SSH.
3> How many concurrent connections does the SSH server takes.

Please help us in order to find out the above details.

Thanks & Regards,
Kedar B.

Hi Kedar,

Let me try answering:

1. Can you provide more details? Does the connection break at same period of time? Can you try setting Timeout property to 0?

Also, when the connection breaks, do you receive any errors?

2. I'm not really sure what you mean by this question. Can you please explain this one?

3. This depends on SSH Server configuration.

Regards,
Damba

Hi,

1> The disconnections are happening recently, it seems our clients are increasing, hence the SSH connections. In some cases we get the errors like Connection is Busy, Time out errors, or just the disconnect event.

2> Currently we had installed the SSH software on the Virtual and Physical servers. As per my understanding, Virtual servers does not gives good performance as compared to physical servers. Is it good, to install the SSH server on a virtual server, is this creating a problem for disconnections

3> What other information would you like to have, so that we can come to know how many concurrent connections the SSH server takes or what is the maximum limit that the SSH server can handle concurrent connections.

Is there any pre-requisite or configuration document related to SSH Server. Iam asking the document, because i want to verify whether the SSH servers are configured properly to take load of the increasing connections. Since the SSH servers are not configured by me, i want to verify the issue.

Thanks & Regards,
Kedar.

Kedar,

Ok, regarding the first issue, I would suggest that you try some other software, let's say Putty and try the same. Does the connection error still occur?

You mention Timeout error, and simple disconnect. This could be due to client timeout or server timeout. To avoid client from timing out, you could try setting Timeout property to 0. Server side inactivity timeout can only be modified on server.

Also, can you try tracing the problem more exactly. Where does the code happen? On what method, etc.?

Regarding Virtual vs. Physical server. This shouldn't pose a problem. Virtual servers should work ok as long as the machine the server is running on has enough power to keep it steady. This ofcourse depends on the machine itself. We personally also have one Virtual server, and I really can't say we experienced this type of problems with it.

What server are we talking about? If it's our wodSSHServer, then there is no limit of this sort. If it's some other solution, then perhaps you should contact your server admin for those informations.

Regards,
Damba

Hi Damba,
Thanks for the answers, i will set the time out to 0, but i will require time of 2 to 3 days to get back the results. I will let you know if iam able to get more details of the issue.

Thanks & Regards,
Kedar.

Hi,
The exact location of error is when we are getting the channel stopped event and error we are getting is 'Server refused remote port forwarding'. Such errors are majorly coming, what could be the issue.

Thanks & Regards,
Kedar.

Kedar,

Did you try our samples? Does the same happen with them?

Can you show me the exact line of the code, when it breaks?

regards,
Damba

Hi,
The code which i had used for our application, is from the sample itself. We are getting the error in this function, which is from the sample

void __stdcall DispChannelStop(wodSSHTunnelCOMLib::IChannel *Chan, short ErrorCode, BSTR ErrorText)

The error text says that the server had refused remote port forwarding.

Thanks & Regards,
Kedar.

Kedar,

Error is received all time when you try to connect and make tunnel with that server or occasionally?

If problem happened all time, maybe port forwarding is disable on that ssh server. Or maybe server doesn't support port forwarding.

Drazen

Hi,
The error comes occasionally, because the application is able to create tunnel as well as channels properly but after an hour, the channel gets automatically disconnects, with the given error. If the server does not supports port forwarding, then it must give me an error, during the time the application creates the tunnel and channels, but it gives the error after few hours. Is there any settings or configuration that we can check to find whether the server supports proper port forwarding.

Thanks & Regards,
Kedar.

Kedar,

If tunnel is working for some time than your server supports port forwarding.

Can you please check if this period of time when wodSSHTunnel disconnect has same duration?

Maybe there is some setting in your server that disconnect tunnel at some particular time.

Which server you are using? Can we maybe connect there and duplicate your problem?

You can send your private information to techsupport@weonlydo.com

Drazen

Hi,
Since i had not installed the servers, i do not no the exact information,but i can provide you the version info which is as follows

SSH-2.0-VShell_3_0_0_439 VShell

For giving other information, i need to take prior permission from the managment. I will let you know the status.

In the mean time i will send you the code, that we are using and its explanation. If you guys can check the code, it might be possible that i might be doing something wrong, that will help me to fix the issue.

Please tell me, how should i send the code, for e.g the email id ,subject etc.

Thanks & Regards,
Kedar.

Kedar,

Please send it to:

techsupport@weonlydo.com

Drazen