Previously working network config fails after upgrading to 25.12-rc1 on mt3000

Installing and Using OpenWrt
1

So I tried upgrading my mt3000 that acts as as a bridged ap with multiple vlans from 24.10 to 25.12-rc1. That resulted in a softbrick.

Resetting the device and doing stuff step by step, I get stuck as soon as I try to add the vlans from the previous config, I lose network access to it (which, lacking serial console, is painful...).

Working: bridged ethernet like so

config interface 'loopback'
        option device 'lo'
        option proto 'static'
        list ipaddr '127.0.0.1/8'

config globals 'globals'
        option dhcp_default_duid '000466bd6b5b78974c759dded7e2bfa9505a'
        option ula_prefix 'fd38:78e4:6f0e::/48'

config device
        option name 'br-lan'
        option type 'bridge'
        list ports 'eth1'
        list porrts 'eth2'

config interface 'lan'
        option device 'br-lan.1'
        option proto 'static'
        option ipaddr '192.168.1.7'
        option netmask '255.255.255.0'
        option ip6assign '60'
        list dns '192.168.1.1'
        option gateway '192.168.1.1'

config bridge-vlan
        option device 'br-lan'
        option vlan '1'
        list ports 'eth0:u*'
        list ports 'eth1:u*'

but as soon as I add another vlan (copy pasting from the old config that still works on the spare mt3000 running 24.10.5), I lose connection to the device. What am I missing / what changed?

config bridge-vlan
        option device 'br-lan'
        option vlan '10'
        list ports 'eth0:t'

config interface 'vlan10routediot'
        option proto 'none'
        option device 'br-lan.10'

config device
        option name 'br-vlan10routediot'
        option type 'bridge'
        list ports 'br-lan.10'
OpenWRT 25.12 - wireless issues with working config in 24.10-SNAPSHOT
2

I surmise you're connected to eth0?

3

Typo rr

Not sure but are names of interfaces of 15 characters or more allowed or was that in the past?

I think you have two ports but are mention eth0, eth1 and eth2 ?

1 Like
4

I though the limit was 8, but couldn't locate the documentation. The user said it previously worked though.

1 Like
5

It did previously work, OTOH, log indeed shows:

Mon Dec 22 14:21:56 2025 daemon.warn netifd: Cannot set device name: 'br-vlan10routediot' is longer than max size 15

Shortening it seems to have worked. Still, odd that it now fails completely whereas previously it worked and no log messages I could find on 6.6.X, either.

Thanks for the pointer, possibly this needs to be addressed in a README?

1 Like
6

The problem is likely the nested bridges...

Remove this entirely:

Also probably best to change the interface name to simply iot:

config interface 'iot'
        option proto 'none'
        option device 'br-lan.10'

And then update the wifi SSID's network name accordingly.

2 Likes
7

Wonderful! :partying_face:

The Linux kernel limits the physical interface name length to max 14 usable characters including the automatically added prefix that is added for some protocols (e.g.6in4, pppoa-, pppoe-, gre4t-) or with bridges (br-).

Depending on the protocol type, the logical interface name may thus be limited to only 8 characters. E.g. abcde6789 is a valid interface name for a normal interface using dhcp, but not for a pppoe interface where the final name would be pppoe-abcde6789, which is more than 14 chars.

~ From the warning at: https://openwrt.org/docs/guide-user/network/network_configuration#section_interface

8

Then I remain confused why 6.6.X did not fail on that?

It was definitely the long name, but will try to simplify, thanks. Don't remember why I had them in the first place.

Still confused why the same config was fine in 6.6, but hey, I will adapt the other devices before I update :slight_smile:

1 Like
9

I don't know why it worked in 24.10, but even on that version I would have made the same suggestions. You have a nested bridge which shouldn't be there in the first place.

3 Likes
10

In any case, I fixed it on all my devices and they then cleanly upgraded to 25.12-rc1 (exception is the BPI R4 where I run into impossible package selection).

Thanks a lot!

11

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