I have recently identified an issue that causes the IPv6 connection to fail or stall within the hardware acceleration engine (PPE) of the MediaTek Filogic processor in the Flint 4 router—specifically when using an SFP+ XGS-PON module with a PPPoE connection configuration. So far, I have only observed this problem when the connection is established via the 10 Gb SFP+ module (everything appears to work correctly when using the 10 Gb Ethernet port).
The issue stems from the fact that, when handling IPv6 traffic encapsulated over PPPoE, the hardware acceleration engine incorrectly calculates or drops packets that exceed a certain size, which causes both download and upload speeds to be cut in half.
After conducting several tests, I managed to find a temporary workaround by manually configuring certain parameters on the router via the LuCI console—specifically, by adjusting and limiting the MTU value to bypass this hardware restriction. This allows for full wire-speed processing without any packet corruption. (I would be happy to share these settings if anyone else is experiencing the same issue.)
I have also submitted a report to GL.iNet to see if their technical department can reproduce the fault and provide a fix. Given that the router has only recently hit the market and there have been very few firmware updates since its launch, I expect this might take some time. Therefore, I would like to know if anyone else has encountered or noticed this same problem and found a similar solution. by this way we could provide more information to GL.iNet, which might help them arrive at a definitive fix more quickly.
We have noted that you also contacted us by email. Please continue working with our support team through the ticket system so we can assist you more effectively. Our technical team will review the issue and follow up with you by email.
This post will remain open in case other users wish to share additional suggestions.
I’ve just replied to your colleagues with the information they requested. I started this thread specifically for this reason—to see if anyone else has encountered this issue and might be able to provide additional details that I may have overlooked.
As an extra detail that might be helpful: I just tested version 4.11.0 Beta4—which includes the Mesh feature to see how it performs. It seems the issue with IPv6 and acceleration doesn't occur here; however, I’ve discovered another significant bug. When using the "Private DNS" option in the main console, making any changes whether in the general DNS tab or the Private DNS tab causes the router’s configuration to become corrupted.
I tested this in two ways: by updating to version 4.11.0 and carrying over my previous configuration, and by setting up the router from scratch. In both cases, as soon as any DNS parameter is modifiedespecially regarding security DNS settings internet access breaks completely; either pages won't load at all, or they load extremely slowly. Even after resetting DNS options to its default settings, the issue persists. Once the router’s configuration is corrupted, there’s no way to restore previous settings. I’m not sure if this bug has already been reported, but it’s similar to the IPv6 issue in the previous version: once the error occurs, there’s no way to revert to a working state.
Thank you for the additional information. Could you clarify what you mean by “Private DNS”? If possible, please also provide the detailed reproduction steps and screenshots of the relevant DNS settings so that we can reproduce the same configuration.
If you are referring to DNS → Manual DNS / Encrypted DNS, we have tested this internally on firmware 4.11.0 Beta4, and it appears to work normally in our test environment. The additional details would help us identify what may be different in your setup.
Yes i´m referring to DNS / Manual DNS / Encripted DNS i´ve checked with both ways, making all the configuration from the begening or direcly upgrading with the old config from version 9.2.
The configuration that actually i´m using "Included Fix" i´ve send you by e-mail, so you can import it directly under this Beta version for cant test, the browser is M$ Edge and Google Chrome both with the latest version, and actually i´m using the "Quad" DNS Provider, normally the Encrypted DNS is leaved as default cause i´m using only the regular one (but i´ve seen that by default is selected a DNS provider and don´t allow to disable this option for use only the regular one.
Thank you for providing the backup. We imported it into our test router and were able to reproduce the DNS resolution issue.
After checking the configuration, we found a legacy firewall.vpnclient entry retained in the backup. It repeatedly reloads the network and DNS services when the firewall configuration is applied. As a temporary workaround, please connect to the router through SSH and run:
uci set firewall.vpnclient.enabled='0'
uci commit firewall
reboot
The router will temporarily go offline while it reboots. After it comes back online, please configure Encrypted DNS again and check whether DNS resolution works normally.
As v4.11 includes substantial changes, including an upgrade of the underlying OpenWrt base from OpenWrt 21 to OpenWrt 25, we recommend performing a factory reset and configuring the router manually. Please do not import the backup created on the older firmware into v4.11 again, as it may restore incompatible legacy settings.
i´ll try the fix that you´re referring for, any way remenber that as i´d told you previosly i already have done with a clean conf. from factory default, and configuring everything manually from the begening as you suggest.
I´s true that doing like this it takes a little bit more time but finally it finish giving the same issue, being the DNS cifrated table corrupted.
Anyway i´ll try again doing your temporary solution, and also from factory reset and i´ll check if some of my defaults confs. could affected it in some way.