Two openwrt routers on the same network have packets dropping out

Hi guys,
I have two zbt-we826t-16m routers running openwrt 22.03.3

When only one router is connected to the home network, there are no issues, the router runs perfectly as expected. No packets dropping out, etc.

But when I connect two routers with the same firmware to the same network, the internet connection on both the routers keep dropping out. The ping test to the wan side of the router reveals that there is always more than 50% packets dropped.

I have tried 6 routers in pairs so far but I see the same issue. As soon as I disconnect one of them, the connection is stable again and there are no packets lost in the ping test.

What is the purpose of the second router?
Often, a second router is used as a dumb AP. OpenWrt's default configuration is setup as a router, not a dumb AP (it is easy to make it into a dumb AP, of course).

If you connect 2 OpenWrt routers in their default (or relatively near default) configurations to the same network, the behavior you are describing is completely expected for two reasons:

  1. The default address for OpenWrt is 192.168.1.1. You cannot have two or more devices using the same IP address -- doing so will cause a collision and exactly the behavior you are observing.
  2. By default, OpenWrt has the DHCP server enabled. Only one DHCP server can be active on a network -- multiple DHCP servers will cause additional conflicts and thus network issues.
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Another common cause for problems would be cloned (backup-/ restore) settings, which may contain MAC addresses - and there mustn't ever be duplicate MAC addresses on the same network.

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Sorry @psherman for the lack of clarity. I meant that the wan side of these two routers are connected to the same network.

@slh You are correct, I see that the wan interface/ network device had the same mac address on both the routers.
On investigating, I found that the single VLAN (eth0.10) I have setup, takes the hardware (or label) mac address by default. I can also see that eth0 has the hardware mac address.
Is there a way I can instead set this hardware mac address automatically to the wan interface / network device (eth0.2) and a random or static mac address for the VLAN device?

reset both routers to their default states. They should read the hardware MAC address from the factory data partition.

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Is it possible to set a different static mac address for the vlan device?

Yes, option macaddr, and with VLANs this can be necessary - but you still should get to the original hardware MAC as well.

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Before asking the question, I had tried the following in /etc/config/network, but it didn't work:

config switch_vlan
        option device 'switch0'
        option vlan '3'
        option ports '6t 3t'
        option vid '10'
        option macaddr 'EE:FF:EE:FF:EE:FF'

The VLAN still got the hardware mac address after reboot.

Is there a different place for setting mac addresses for VLANs?

It needs to go into the interface stanza, next to the IP address of your VLAN.

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