Build for Fritzbox 4040, switch and LUCI working

Hey Thomas, after trying many days to implement a VLAN an my FritzBox 4040 i found this thread an it works! Many thanks.

Are you willing to do this magic kind of stuff with the latest firmware?

Hi Gustavoo,
I have a 21.02.0 build, and it basically works, not much testing done till now.
Your feedback would be welcome ...


You could also have a look here:



Hi Thomas,

I just got a new FB4040, ran into the same VLAN troubles, and just ended up having to go into rescue mode to pseudo-fix it. :expressionless: so, first of all, thank you for making this! Any chance of a 21.02.1 build, and perhaps a custom attendedsysupgrade URL for future builds? Also, since you're linking to that other thread, is the implication that these builds from over there should work directly on the FB4040? (I'm guessing not, but it's been a loooong time since I last used OpenWRT)

Also, one thing I noticed:

The MTU setting on this device seems to malfunction weirdly, at least with the official build. Configure an MTU of 9018, jumbo frames stop working. Configure no MTU at all, jumboframes work just fine-->wth?

Here is my (untested) 21.02.1 build, just compiled but not flashed yet.
I never touched MTU size as I have no need for jumbo frames.
I've tried notengo's build, working fine, but for me, too much stuff inside.
In between he also offers a "slim" version of his build.

One question:
How did you manage to get into rescue mode on the FB4040 ?


Update, now with links.


Thank you, but I think you accidentally didn't post the actual link? As for the rescue mode, I just followed the generic rescue mode instructions while guessing that the WPS button would be the one to accomplish the task, which it indeed was.

updated my previous post (now with links)

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I have this router with last official version of openWRT installed, 21.02.1 from the official builds to it.

I have found your post, and feel curiosity.

What are the advantages of your build over the official build?


The only advantage is that you can configure VLANs from the GUI.

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Thank you, I am not using VLANS for now, as I don't need to separate traffic from different ports, just traffic from different wifi networks (at least for now, until I have a IOT device with no wifi interface and a ethernet interface). So it won't be of use for me.

Thank you for the answer.

Hi tomtom,
How you are building the new images for 21.02.1 to be specific how to handle the patch
"715-net-essedma-disable-default-vlan.patch" --> target/linux/ipq40xx/patches-4.14
patches-4.14 do not exist in 21.02.1 ...
Here you have patches-5.4?
Thanks for you help

Well I have finally created VLANS in the Fritz!bos in order to get separate guest, lan and iot networks.

It was a headache, due to the problem of not being able to change vlan in position 1 and 2 that is hardwired and turns the device unreachable until you reset it in failsafe mode.

I had not realized about that problem, I thought this built was only to be able to connect vlans to ethernet port.

I have solved it right now editing the network file and configuring the position of the vlans manually (which is different from the vlanid and which luci tends to use in position 1 and 2 even if vlanid is different).

Does this firmware solve that problem and let you configure vlans from luci without changing 1 and 2 vlan tables?

May I install it easily over the current openWRT 21.02 version conserving the config?

May I expect to see this solution integrated in the mainstream for this router in the near future?

The problem of installing it is that you won't be able to upgrade later when there are important changes in the main stream version.

Is it converted to DSA with separate lan1, lan2 etc ports or yet using eth0 switeches?
And the wan port?

Hi ChriWo,
for 21.02.1 you need this patch.


Hi Fernando,
my build isn't using DSA but swconfig.
You can use any VLAN on any port (even 1 and 2)

Be aware that you MUST NOT keep settings as the LAN/WAN ports have changed.

LAN is now eth0.1 (was eth0)
WAN is now eth0.2 (was eth1)


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I have now it working with the standard distribution.
I am afraid of changing something and being not able to get it to work.

But it sounds very interesting and it seems to solve most of the problems that this chipset had when using WAN port and VLANs.

Thank you to you and notengowifi for the work.

I hope we can see this in future upgrades.

I know that they are working on converting the ipq40xx architecture to DSA. Am I right to assume that this patch and therefore this custom build will not be needed anymore when it is commited? Pull request for DSA conversion

That would be great, and see it integrated in main stream, to be able to upgrade without worries.

good afternoon,
I would like to create a Lan2 and I need help since I can't do it without running out of internet.
My openwrt is installed on a Fritzbox 4040.
I have tried to create a new VLAN in the Switch tab but then I cannot configure it
If someone could help me