TimeOut in Connect on iOS

[TomQv]

I'm only receiving Timeout-Exception trying to connect to my ftp-server with iOS:

var client = new SftpClient("files.qvgps.com", “user”, “password");
client.Connect();

Renci.SshNet.Common.SshOperationTimeoutException: Connection failed to establish within 30000 milliseconds.
  at Renci.SshNet.Abstractions.SocketAbstraction.ConnectCore (System.Net.Sockets.Socket socket, System.Net.EndPoint remoteEndpoint, System.TimeSpan connectTimeout, System.Boolean ownsSocket) [0x000a4] in <f1d5e967bcbc48fcb33dd5c4b79edfbe>:0
  at Renci.SshNet.Abstractions.SocketAbstraction.Connect (System.Net.Sockets.Socket socket, System.Net.EndPoint remoteEndpoint, System.TimeSpan connectTimeout) [0x00000] in <f1d5e967bcbc48fcb33dd5c4b79edfbe>:0
  at Renci.SshNet.Connection.ConnectorBase.SocketConnect (System.Net.EndPoint endPoint, System.TimeSpan timeout) [0x0000e] in <f1d5e967bcbc48fcb33dd5c4b79edfbe>:0

With UWP, it works fine.

SSH.NET 2024.1.0
Visual Studio Community 2022 for Mac
Version 17.6.12 (build 410)
Xamarin.iOS
Version: 16.4.0.23 Visual Studio Community

Are there maybe any additional steps required on iOS to use sftp?

[TomQv]

Ok, did some more tests, seems like is was my router. I disconnected from Wifi and used mobile data, then it worked. Then I restarted my router and then it also worked with Wifi. No timeouts anymore.
Strange, but it looks like, as it was no SSH.NET problem.

[Rob-Hague]

Yeah so despite the stack trace the real problem is waiting too long in Socket.Connect:

SSH.NET/src/Renci.SshNet/Abstractions/SocketAbstraction.cs

Lines 88 to 90 in 3dda5c9

	throw new SshOperationTimeoutException(string.Format(CultureInfo.InvariantCulture,
	"Connection failed to establish within {0:F0} milliseconds.",
	connectTimeout.TotalMilliseconds));

I imagine (or hope) you would observe a similar hang without the library:

using System.Net.Sockets;

using var socket = new Socket(SocketType.Stream, ProtocolType.Tcp);

socket.Connect("files.qvgps.com", 22);