I've a setup with a main router as a VM (x86), now upgraded to OpenWrt 25.12.5.
The br-lan is a bond of eth1 and eth2 (eth0 is connected to the ONT).
There are several other APs upgraded all to OpenWrt 25.12.5.
Previously all the were OpenWrt 25.12.3.
When I upgraded all them to OpenWrt 25.12.5, I discovered that one of them breaks the network if I upgrade it to OpenWrt 25.12.4 or OpenWrt 25.12.5. OpenWrt 25.12.3 works fine.
The guilty seems to be an older Mikrotik RouterBOARD 951G-2HnD, which I use in an isolated room where very few devices are connected (so that's why I keep using that older AP).
It seems that the Mikrotik is somehow killing the network in such way that the main router (x86 VM) complains several times per minute:
[6 jul 2026, 9:12:53 CEST] kern.warn: [67013.114182] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:54 CEST] kern.warn: [67013.323314] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:54 CEST] kern.warn: [67013.775962] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:55 CEST] kern.warn: [67014.326134] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:55 CEST] kern.warn: [67014.411228] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:55 CEST] kern.warn: [67014.644045] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:55 CEST] kern.warn: [67015.230787] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:56 CEST] kern.warn: [67015.366075] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:56 CEST] kern.warn: [67015.445999] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:56 CEST] kern.warn: [67015.655591] br-lan: received packet on bond1 with own address as source address (addr:a8:b8:e0:03:e0:95, vlan:0)
[6 jul 2026, 9:12:59 CEST] kern.warn: [67018.495936] net_ratelimit: 7 callbacks suppressed
What confuses me is that MAC addresses are different, and especially that this only happens when I upgrade the Mikrotik to 25.12.4 or 25.12.5. What changed from 25.12.3 affecting this?