System.Net.Sockets.SocketException (10060)

I am getting System.Net.Sockets.SocketException (10060), while downloading the files from SFTP into Azure Blob storage using C#, and this code is working fine in my local machine(running manually in Visual Studio 2019), but the problem is after published my code into WebJobs it’s getting failed and giving attached Errors.

[05/23/2020 15:31:16 > 36bfb3: SYS INFO] Status changed to Initializing
[05/23/2020 15:31:16 > 36bfb3: SYS INFO] Job directory change detected: Job file 'FileDownloader.dll' timestamp differs between source and working directories.
[05/23/2020 15:31:16 > 36bfb3: SYS INFO] Run script 'run.cmd' with script host - 'WindowsScriptHost'
[05/23/2020 15:31:16 > 36bfb3: SYS INFO] Status changed to Running
[05/23/2020 15:31:17 > 36bfb3: INFO] 
[05/23/2020 15:31:17 > 36bfb3: INFO] D:\local\Temp\jobs\triggered\FileDownloader\v1dgfgmq.hla>dotnet FileDownloader.dll  
[05/23/2020 15:31:39 > 36bfb3: INFO] An exception has been caught System.Net.Sockets.SocketException (10060): A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
[05/23/2020 15:31:39 > 36bfb3: INFO]    at Renci.SshNet.Abstractions.SocketAbstraction.Connect(IPEndPoint remoteEndpoint, TimeSpan connectTimeout)
[05/23/2020 15:31:39 > 36bfb3: INFO]    at Renci.SshNet.Session.SocketConnect(String host, Int32 port)
[05/23/2020 15:31:39 > 36bfb3: INFO]    at Renci.SshNet.Session.Connect()
[05/23/2020 15:31:39 > 36bfb3: INFO]    at Renci.SshNet.BaseClient.Connect()
[05/23/2020 15:31:39 > 36bfb3: INFO]    at FileDownloader.WithSSHHostKey.DownloadFiles() in D:\<I am getting here local solution path even it's ran through webjob>\WithSSHHostKey.cs:line 29
[05/23/2020 15:31:39 > 36bfb3: SYS INFO] Status changed to Success

what is the issue here ?.

[sachetpatil1]

@dineshclinton After so much investigation, we decided to speak with our Azure admin team (different organisation) and got to know that they restricted FTP server to connect external resourves in firewall so that App service IP was not allowed to connect FTP server. We requested them to whitelist that IP and it worked.

In short, there is no issue in Renci dll regarding connection to external ftp. Now we are able to send all files but not sure how much file size it can handle (Curently we are sending max 100 mb file).

Let me know if this resolved your query and sorry for delayed reply 😦

[zg18aam]

This is a firewall issue. Adding a firewall rule to allow the IP of the application server / local machine would allow the smtp host to connect. After that include protocol logger too to check the logs,