SoftEther VPN User Forum

Hi there!
I have a problem which I was unable to fix. I have a server running at home, and I connect to it when I'm abroad.
Lately I got a new laptop: Asus Zenbook 14 UX3402VA-KP144W.
Specs (In case it's related: Intel® Core™ i5-1340P, intel wifi 63 ax211 160hz, Windows 11).
The laptop is working fine , everything is fast and stable including connectivity... until I use SoftEther.
I use the default settings, it connects just fine, and my other laptops connect just fine... but the new Asus laptop - no go.
I don't think there is anything wrong hardware wise because there are zero issues besides SoftEther.
I tried disabling windows firewall and I don't have 3rd party antimalware\firewall installed.
Please save me and help me find the cause before I sell this laptop and lose money.
Thanks!!

Server log:
2023-07-13 16:04:58.517 On the TCP Listener (Port 0), a Client (IP address 46.154.72.76, Host name "46.154.72.76", Port number 21763) has connected.
2023-07-13 16:04:58.517 For the client (IP address: 46.154.72.76, host name: "46.154.72.76", port number: 21763), connection "CID-3-A7C6BA3D9F" has been created.
2023-07-13 16:04:58.709 SSL communication for connection "CID-3-A7C6BA3D9F" has been started. The encryption algorithm name is "TLS_AES_256_GCM_SHA384".
2023-07-13 16:04:58.904 [HUB "Home VPN"] The connection "CID-3-A7C6BA3D9F" (IP address: 46.154.72.76, Host name: 46.154.72.76, Port number: 21763, Client name: "SoftEther VPN Client", Version: 4.41, Build: 9787) is attempting to connect to the Virtual Hub. The auth type provided is "Password authentication" and the user name is "das".
2023-07-13 16:04:58.904 [HUB "Home VPN"] Connection "CID-3-A7C6BA3D9F": Successfully authenticated as user "das".
2023-07-13 16:04:58.904 [HUB "Home VPN"] Connection "CID-3-A7C6BA3D9F": The new session "SID-DAS-4" has been created. (IP address: 46.154.72.76, Port number: 21763, Physical underlying protocol: "VPN over UDP with NAT-T (IPv4)")
2023-07-13 16:04:58.904 [HUB "Home VPN"] Session "SID-DAS-4": The parameter has been set. Max number of TCP connections: 2, Use of encryption: Yes, Use of compression: No, Use of Half duplex communication: No, Timeout: 20 seconds.
2023-07-13 16:04:58.905 [HUB "Home VPN"] Session "SID-DAS-4": VPN Client details: (Client product name: "SoftEther VPN Client", Client version: 441, Client build number: 9787, Server product name: "SoftEther VPN Server (64 bit)", Server version: 441, Server build number: 9782, Client OS name: "Windows 11", Client OS version: "Build 22621, Multiprocessor Free (22621.ni_release.220506-1250)", Client product ID: "--", Client host name: "elenar", Client IP address: "192.168.27.163", Client port number: 50353, Server host name: "AAA.BBB.CCC.DDD", Server IP address: "AAA.BBB.CCC.DDD", Server port number: 5555, Proxy host name: "", Proxy IP address: "0.0.0.0", Proxy port number: 0, Virtual Hub name: "Home VPN", Client unique ID: "ZZXXCCVVBBNNMM")
2023-07-13 16:04:59.647 [HUB "Home VPN"] Session "SID-LOCALBRIDGE-2": The DHCP server of host "8C-53-C3-9D-C0-FE" (192.168.31.1) on this session allocated, for host "SID-DAS-4" on another session "5E-06-8A-AB-EE-2F", the new IP address 192.168.31.19.
2023-07-13 16:05:23.524 [HUB "Home VPN"] Session "SID-DAS-4": The session has been terminated. The statistical information is as follows: Total outgoing data size: 15167 bytes, Total incoming data size: 7218 bytes.
2023-07-13 16:05:23.549 Connection "CID-3-A7C6BA3D9F" terminated by the cause "The VPN session has been deleted. It is possible that either the administrator disconnected the session or the connection from the client to the VPN Server has been disconnected." (code 11).
2023-07-13 16:05:23.549 Connection "CID-3-A7C6BA3D9F" has been terminated.
2023-07-13 16:05:23.549 The connection with the client (IP address 46.154.72.76, Port number 21763) has been disconnected.

Groot wrote: ↑

Fri Jul 14, 2023 1:59 pm

Physical underlying protocol: "VPN over UDP with NAT-T (IPv4)"

This is unreliable. Try physical underlying protocol: "Standard TCP/IP (IPv4)" instead. While at it, post a successful log when using the old laptop _AND_ connecting from the same client ISP to the same VPN hub.

Hi Solo, thanks for helping.

Bad log from new laptop:
2023-07-14 12:42:04.866 SoftEther VPN Client Version 4.41 Build 9787 (English)
2023-07-14 12:42:04.866 Compiled 2023/03/14 11:00:03 by buildsan at crosswin with OpenSSL 3.0.7
2023-07-14 12:42:04.866 The SoftEther VPN Client Engine has been started.
2023-07-14 12:42:04.963 Loading configuration file...
2023-07-14 12:42:04.966 Configuration file does not exist. Applying the initial settings.
2023-07-14 12:42:04.967 Monitoring the directory "C:\Program Files\SoftEther VPN Client". If the amount of available free disk space becomes less than 8.00 GBytes, the backup files for log files and configurations that are saved on the sub-directories of this directory will be automatically deleted in the order of oldest first. The amount of free disk space that determines when to start deletion can be modified by changing the "AutoDeleteCheckDiskFreeSpaceMin" item in the configuration file.
2023-07-14 12:42:47.370 A Virtual Network Adapter "VPN" has been created.
2023-07-14 12:46:00.301 A new VPN Connection Setting "New VPN Connection" has been created.
2023-07-14 12:46:06.420 Connection processing for VPN Connection Setting "New VPN Connection" has started.
2023-07-14 12:46:06.420 VPN Connection Setting "New VPN Connection": Connection operation starting (this is now 1 times).
2023-07-14 12:46:09.652 VPN Connection Setting "New VPN Connection": Now connected. Session name: "SID-XXXX-12"
2023-07-14 12:46:42.603 VPN Connection Setting "New VPN Connection": The connection has been either disconnected or it failed. Cause: Time-out occurred during VPN session communication. It is possible the connection from the client to the VPN Server has been disconnected. (code 13)
2023-07-14 12:46:45.575 VPN Connection Setting "New VPN Connection": Connection operation starting (this is now 2 times).
2023-07-14 12:46:48.925 VPN Connection Setting "New VPN Connection": Now connected. Session name: "SID-XXXX-13"
2023-07-14 12:47:21.865 VPN Connection Setting "New VPN Connection": The connection has been either disconnected or it failed. Cause: Time-out occurred during VPN session communication. It is possible the connection from the client to the VPN Server has been disconnected. (code 13)


Good laptop log:
2023-07-14 08:37:18.666 SoftEther VPN Client Version 4.42 Build 9798 (English)
2023-07-14 08:37:18.666 Compiled 2023/06/30 11:06:58 by buildsan at crosswin with OpenSSL 3.0.9
2023-07-14 08:37:18.666 The SoftEther VPN Client Engine has been started.
2023-07-14 08:37:18.809 Loading configuration file...
2023-07-14 08:37:18.809 Monitoring the directory "C:\Program Files\SoftEther VPN Client". If the amount of available free disk space becomes less than 8.00 GBytes, the backup files for log files and configurations that are saved on the sub-directories of this directory will be automatically deleted in the order of oldest first. The amount of free disk space that determines when to start deletion can be modified by changing the "AutoDeleteCheckDiskFreeSpaceMin" item in the configuration file.
2023-07-14 08:37:18.809 The configuration file has been loaded.
2023-07-14 12:00:56.253 Connection processing for VPN Connection Setting "New VPN Connection (2)" has started.
2023-07-14 12:00:56.253 VPN Connection Setting "New VPN Connection (2)": Connection operation starting (this is now 1 times).
2023-07-14 12:00:58.051 VPN Connection Setting "New VPN Connection (2)": Now connected. Session name: "SID-ZZZZ-10"
2023-07-14 12:33:02.203 VPN Connection Setting "New VPN Connection (2)": The connection has been either disconnected or it failed. Cause: The VPN connection was disconnected because the system is being suspended. (code 148)
2023-07-14 12:39:17.499 VPN Connection Setting "New VPN Connection (2)": Connection operation starting (this is now 2 times).


1. I'm not at home so I didn't test "Standard TCP/IP (IPV4)" yet, but I thought I will share the logs in the meanwhile.
2. I'm aware the SoftEther version is different. I believe I tried 9798 and actually tried the older version to see if other builds work on the new laptop, but I will verify just in case.


Thanks again!

Hi, please check if VPN Gate TCP, non-NAT-T connections work. Get it from https://www.vpngate.net/en/download.aspx

Hi,
Connecting using VPN Gate worked, but it was painfully slow (I guess because all the servers in the list are far away) compared to the other laptop which was connected normally.
But it is interesting that it managed to connect and stay connected.
Maybe it will give you ideas for a solution.
I am thankful your effort.

Forward port 5555 on your SE server's router, disable NAT-T on SE client, re-test.

Thank you. I will test it tomorrow and update back.

Update:
Port forwarding of 5555 fixed the issue regardless of disabling NAT-T on the SE client. Thank you very much for your help Solo.
What I don't understand is why the other laptops connect just fine on the same port.
I mean, if it's a server env configuration issue, shouldn't it affect the other clients?

I suppose your router(s) kept old NAT-T ports opened and blocked new connections.