Hi, I just read on the GL Internet website that OpenVPN is supposed to run at up to 880 Mbps with DCO support.
What is "DCO Support"? Where can I find it, or what settings do I need to adjust to make it work that fast?
Or is it different firmware?
Since I have absolutely no idea what this is, I really need some help.
OpenVPN Data Channel Offload: Unleashing Superior VPN Performance.
Needs to be enabled on server side, so not sure if big providers use it.
Thanks for the link, but I still don't understand it. Maybe it's the translation.
Does it need to be installed on the Flint? If so, what are the commands for OpenWRT?
It's a special kernel module that's baked into the kernel. You need to compile the OpenWrt kernel with the correct dco functionality then: OpenVPN dco how to enable? - #33 by vochong - Installing and Using OpenWrt - OpenWrt Forum
All in all it's not needed nor very useful.
Please upgrade to the latest v4.8.3 firmware for Flint2 and it supports DCO of OpenVPN, which is pre-installed in the firmware.
The VPN server still needs to support DCO in order to enable DCO on the tunnel to increase speed, I mean if the Flint 2 works as VPN client.
disable-dco and compress parameters do not exist in the server push or client profile.Okay, I'll do it right away later. Does the current snapshot already have that feature?
I use NordVPN and Surfshark; do you know if they have it?
As far as is known, they appear to be supported. We tested in Hong Kong with Mullvad server before, it is good about 0.9 or 1 Gbps in Flint2 with DCO, but for NordVPN and Surfshark, even though DCO is supported in server and client (Flint2), the speedtest is not fast which taking about the VPN tunnel. This may be related to server load, server resource allocation, and account level (traffic priority). The speed is similar to ordinary OpenVPN.
If you want the ultimate DCO speed, like the lab, we recommend self-hosting the OpenVPN DCO server.
Or consider using WireGuard. Its speed performance is usually better than OpenVPN. Of course, it also depends on the service providers. More and more service providers prefer server resources to WireGuard.
I've also used WireGuard, but strangely enough, there are situations where I have problems with WireGuard but not with OpenVPN, even though it's the same server.
I have no idea why.
Will there be any problems if you install WireGuard APP on mobile phone and use the same one VPN profile?
NO
But let me tell you right now that I don't use the provider's apps on any of my devices.
Only the router.
I've now tried it with version 4.8.3, but under Luci it unfortunately shows me this, and I have no idea what it wants.
When I click on Protocol Extensions, a new page appears with numerous installation options, but I have no idea which one I need.
There is no need to configure the OpenVPN in Luci, please configure in the GL GUI.
If the VPN server supports DCO, Flint2 will automatically enable DCO support.
I've now tried using the Flint 2 GUI, and the error message under Luci is still displayed as above.
However, neither Surfshark nor NordVPN achieve speeds above 180 Mbps download and 40 Mbps upload with OpenVPN.
Both support DCO.
With WireGuard, I get over 450 Mbps download and a maximum of 20 Mbps upload.
This is the case, after configuring the OpenVPN in the GL GUI, it will be able to work. Please ignore Luci that it is not compatible with newer versions of the OpenVPN program.
I think the speed is not as expected due to high VPN server resources or overload. How about other VPN servers?
A clean install was attempted, along with numerous different servers. First, I tried NordVPN, and then Surfshark without NordVPN.
The result is always the same: a maximum of 180 Mbps, and then it stops.
Nothing was done to Luci.
If possible, please share your router with us via GoodCloud, I would like to remote check your router.
Please PM me your router MAC address and the Admin Panel password.
Hello, access is currently not possible (for various reasons).
Since I had the flu over Christmas, I had plenty of time to test.
So, with the stable version 4.8.3, OpenVPN only ever works up to a maximum of 180 Mbps and no more.
Regardless of the server or provider.
(NordVPN or Surfshark)
I also tested the beta, the snapshot, and OpenWRT24.
Only the snapshot 4.8.4 (2026-01-01 16:11:15) worked. With that version, OpenVPN went up to the full bandwidth of 350-450 Mbps.
I noticed that, for example, when streaming Disney+, the picture becomes out of sync after a while or freezes completely. This phenomenon only occurs with OpenVPN; when I switch to WireGuard, it disappears.
Hi,
Let’s keep using the snapshot version for now.
BTW, may I know whether IPv6 is enabled on the router?
When this issue reproduces, how is the network condition (e.g., fast.com, speedtest.net)? Is the ping google.com stable? If re-enable the OpenVPN tunnel and how is going?