SoftEther VPN User Forum

Hi folks,
I setup a softether VPN server on my raspberry pi. When I connect the server using softether client, everyting works fine.
However, when I connect the server uing l2tp client on windows 7 paltform, I often encounter the timeout error:
the log info is as follows:
2014-11-10 00:23:40.630 L2TP PPP Session [202.156.91.19:1701]: An IP address is assigned. IP Address of Client: 192.168.16.138, Subnet Mask: 255.255.255.0, Default Gateway: 192.168.16.1, Domain Name: "", DNS Server 1: 114.114.114.114, DNS Server 2: 8.8.8.8, WINS Server 1: 0.0.0.0, WINS Server 2: 0.0.0.0, IP Address of DHCP Server: 192.168.16.1, Lease Lifetime: 86400 seconds
2014-11-10 00:23:40.630 L2TP PPP Session [202.156.91.19:1701]: The IP address and other network information parameters are set successfully. IP Address of Client: 192.168.16.138, Subnet Mask: 255.255.255.0, Default Gateway: 192.168.16.1, DNS Server 1: 114.114.114.114, DNS Server 2: 8.8.8.8, WINS Server 1: 0.0.0.0, WINS Server 2: 0.0.0.0
----------------------the error--------------------------
2014-11-10 00:26:50.750 L2TP PPP Session [202.156.91.19:1701]: A timeout on the PPP data transmitting occurred. The PPP client might be disconnected from the network.
2014-11-10 00:26:50.750 L2TP PPP Session [202.156.91.19:1701]: The PPP session is disconnected.
------------------------the error----------------------
2014-11-10 00:26:53.112 [HUB "VPN"] Session "SID-YANGGIS-[L2TP]-9": The session has been terminated. The statistical information is as follows: Total outgoing data size: 8212601 bytes, Total incoming data size: 547475 bytes.
2014-11-10 00:26:53.143 Connection "CID-11" 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).
2014-11-10 00:26:53.143 Connection "CID-11" has been terminated.
2014-11-10 00:26:53.143 The connection with the client (IP address 202.156.91.19, Port number 1701) has been disconnected.

Can you guys help out, why the connection is frequently timeout?
Thanks in advance.

Any suggestion?

Hi, anybody can help please?

I guess there are something wrong on your network.
Is there packet loss?

Hi, no package loss, I think the PPP session is dead suddently.

Im seeing similar results with softether setup on windows 2012 R2. Speeds are great, but after about 10-15min it'll drop out :(

Actually im seeing this error with any OS I've tried with. Could It be something to do with keepalive? too frequent?

yanggis wrote:
> Hi, no package loss, I think the PPP session is dead suddently.

Hi yanggis,

Have you had any luck with this?

Have you also tried other tunneling software to see if you get the same issues? If so, name the brand of the software that you used on both the server and the client. Also detail the outcomes whether or not if trying out other software succeeded or not.

So far ive tried softether on Windows 2012 and Linux (centos & ubuntu). Doesn't matter what kind of settings I try (virtual nat on/off, DHCP, MTU, keepalive etc) changing in softether, my android & iOS phones keep dropping at random times. They'll stay connected for 1-2hours then drop all of a sudden.

Speeds with softether are great and all sites/apps work perfectly, it just that the phones drop connection and the logs don't say much.

All the correct ports have been forward. Tried firewall disabled/enabled etc etc.

The only other VPN software I've tried is Windows 2012 RRAS. Tweaking the VPN client MTU settings in registry down to 1300/1200, the phones stay connected all day long, but the only thing with this is I am unable to browse some sites like twitter, instagram and have difficulties upload videos etc.

That might be because the TCP window size might be too small. Though this is for the other software, not for SoftEther VPN.

As for SoftEther VPN, there are potentially many ways to try and look at the issue. One of them would be to dump the packets from both the server and the client. With SoftEther VPN Server Manager, go into Log Save Setting and check to save both the security log as well as the save packet log. For every other option check 'Headers & Payloads'. You only need to this for probably one or two connections, so after that restore the settings for your Log Save Setting back to default.

For the client side, perhaps the best way is to run something like wireshark and to see for any clues.

Though for scenarios like this, the information would be verbose however I am unable to help you all that much even if you provided me the logs after you have tried them. There is a chance that it might be something to do with power saving but that is just a random guess.

As the case with your portable devices that are namely running Android and iOS respectively, this could be something to do with power saving for sure. For Android, you can potentially disable power saving but there are no guarantees. As with iOS, I am aware this is probably going a little offtopic but I read this on vpngate.net which might also be related:

"
Geek's question: Why there are some OpenVPN sessions which are disconnected immediately after established with 0.02MB or less traffic?
We recognize that the cause is from a bug of OpenVPN Connect for iPhone. While OpenVPN session is active, OpenVPN tries to keep the VPN connection forever even if iPhone is sleeping. But iOS restraints OpenVPN process to be suspended short time after VPN session establishes. This repeats many times. So our log records very short-time OpenVPN sessions from the same IP address.
"

Even if this case is not to do with short intervals but for over a longer duration, chances are it is to do with the OS settings and namely power settings. A potential way to prevent handhelds from disconnecting might be to keep using as much of the connection as possible, as soon as there is an idle for however long the OS restricts network connections to and/or softwares running in the background the connection would then be dropped.