L2TP/IPSec VPN drops


Hey everyone,

I’m using a Balance One core, and we have L2TP/IPSec vpn users set up that connect remotely from outside the office.

Any sort of large and sustained file transfers seem to cause the VPN clients to disconnect. This has been frustratingly consistent for the client.

Is this to be expected? I changed the MTU to 1492 on the WAN interface, and capped the “Upload” bandwidth at about 80% of our broadband circuit’s upload capacity (I did the same for download, but was told the download cap doesn’t actually do anything).

Does anyone have tips or ideas?


The MTU should be whatever your ISP uses. Are your remote clients connecting via cellular connection? I would suggest you test using an internet connection nearby, not cellular, and try to isolate whether the issue is at the remote or host end.

I’ve used Peplink’s L2TP connection literally from the other side of the world without problems, also using a Balance One at the host end, so don’t give up.


Hey Don,

Thanks for the reply.

Most of my VPN client connections are from Cable/DSL/Fiber (high speed) broadband connections in the US, but this has also happened to VPN clients trying to connect from other countries.

It doesn’t seem to matter where people are – if they try to transfer big files, it seems to kill the VPN connection.

Would love any other ideas you have,


Further investigation need to be done from the device in-order to identify the issue. Please open a support here for support team to check.

Beside that, please include the test scenario that able to reproduce the issue in the support ticket and support team will help to verify on the issue.


This happens to me as well. I have a Peplink Balance 210. Never been able to figure out why it happens. When I’m at home connected to the VPN/Peplink at my office and try downloading larger files to my laptop that’s connected to the VPN 9 times out of 10 the network VPN connection disconnects before the download completes.



  1. What is the firmware version running for you B210 ?
  2. Larger files ? What is the files size ?
  3. The disconnection happen randomly when downloading the files ? Usually how long the VPN client will disconnected?
  4. What the is the WAN health check method configured for the B210 ?
  5. Any event logs generated when VPN clients disconnected ?
  6. The issue happen for different client device as well ?


I have the same exact issue on the Peplink Balance One Core. I’m running firmware 6.3.1 build 2256. I’m connected to a fiber connection on both ends. The fiber is provided by the same provider. Transferring large files or multiple files has a really hard time completing. The VPN connection will terminate in the middle of the transfer. 250 files with a total size of 250mb.



This is a strange one. Our experience is exactly the same as that of @Don_Ferrario. No issues whatsoever – and we have several of these in use. But I sure wish folks to have had such issues would come back and TELL US if/how they were resolved? It helps everyone – don’t just “leave.”

And, just to confirm, these are all L2TP issues being reported, right? Not PepVPN?

@monkthecat What happened? Did you enter a support ticket? What was the result?

@dwpoulin Dean – did you ever answer @sitloongs?

@DanITman Dan, I’m wondering why you are using 6.3.1 Firmware. Your product will support the very latest FW, FYI.


Hey all:

Yeah I have this issue with about 6 different Peplink devices (yes, L2TP, not PepVPN), all running 7.1 firmware, all on different kinds of internet providers. I’ve spent hours on the phone with Peplink support, they have no idea what’s happening.

So I’ve been slowly changing my customers over to Meraki routers, and the problem hasn’t happened a single time, no matter how hard I hammer the VPN connection.

I loved Peplink, so am sad that this seems to be the solve, but that’s where I’m heading.


We are having the same issue balance 305 - L2TP. Running firmware version: 7.1.1



Just to confirm the issue happen after you upgrade to firmware 7.1.1 ?

Please open a support ticket for to allow support team to check from the device.



Hey Rick, as I said in my post: yes I opened many support tickets with support, Peplink had no idea what was causing the drops. My solve has been to replace the Peplinks with either Merakis or Sonicwalls, and I have not had the VPN drop issue once with either platform. So there is no wisdom I have to share here, except that moving away from the Peplink platform was the only way to resolve the issue.