SoftEther VPN User Forum

that's it.
I can access remote LAN IPs and browse shared folders successfully.

As soon as I transfer a file from the server to the client, ping reports timeout, the copy stalls at 0% and I have to wait almost a minute for Windows Explorer copy error message.
After those timeouts, the connection is running normally.

Tried connecting also with Windows native client but couldn't copy the file anyway.

I reconfigured the Server to use SoftEther protocol instead of L2TP but with the same results.

Used HTTP File Server utility to transfer files via HTTP instead of SMB, browser transfer stalls at 0% again.

Server version is v4.2 Build 9608 running on Windows 8.1 x64
Client version is v4.2 Build 9608 running on Windows 10 x64

I also tried with other client PC running Windows 7 x64, same results.

What am I doing wrong?

It might be worth taking a look into the packet_log files on the server and see what is happening.

Out of curiosity. Are both the server and the client ipv4??

Yes, both IPv4.

When running normally, the logfile looks like this:
SYN
SYN+ACK
SYN+ACK
FIN+ACK
FIN+ACK
SYN

Then, when I start the copy, the log changes to this:
RST+ACK
RST
SYN
SYN+ACK
RST+ACK
RST
SYN
SYN+ACK
RST+ACK
RST
SYN
SYN+ACK

I saw that everytime a RST occurs, WindowSize=0 and when there is a SYN or SYN+ACK the WindowSize=8192
Don't know if this is relevant...

Hmm ok.

Are you using secureNAT. In this case what is the current mtu value? If it is very high, Can you set it to 1500 or 1497?

Also could you please post your current SoftEther config file

Regards,
Moataz

I'm not using SecureNAT.

Please take a look at the attached config file, I edited the private bits.

On the first look I can't see anything unusual.

Which protocol are you using for file transfer? ftp?

Are you staring SoftEther using "execsvc" (I assume) or "start"?

What happens if you switch to SecureNAT instead of bridge?

Thank you.

The protocols used where normal Windows SMB, HTTP (using rejetto.com/hfs) and also ftp. the problem occurs everytime.

I was able to copy only a small file like 200/300 kb, if the file is bigger the copy fails.

SoftEther Server starts automatically with Windows.

By your suggestion, I also tried SecureNAT (with disabled Virtual DHCP to avoid conflict) and the result was the same.


Did other test, I made some queries to a SQL Server and got the connection timeout like when I copy files.
Maybe this release is broken?

Ok. I suspect this might be the mtu value somewhere.

To really make sure that of this theory, create a text file with 1 character in it and try to copy it over the network. If this works, this will tell us that the window size/mtu value somewhere is set too high, that the other side can not cope with.

And one more test, connect to the SoftEther server using OpenVPN and UDP (not TCP) and try to copy a small and large file.

MTU=1500 on client and server NIC

What about the other 2 questions?

- transfer a 1 byte file
- Use OpenVPN UDP

1 byte file is OK, 200/300 kb file is OK too but 400kb file it always fails.

Didn't have the chance to test OpenVPN yet but I'm using L2TP which is UDP also.

If you copy 400 kb file, it also failed copy at 0%?

yes, copy fails at 0%. I can only copy smaller files.
Like I previously said, I tested some queries to a SQL Server and also got the connection timeout like when I copy files, so I think the problem isn't related with the copy process, maybe high usage or something.

Umm....
Could you capture packets on virtual NIC by wireshark?

dandan - did you ever get this resolved? I am having a VERY similar issue.