Strange broadcast (UniFi Discovery) on the WAN interface

[OPNuzz]

Hello everyone,

my firewall log is currently flooded with UniFi-Discovery broadcasts. According to Ubiquity these cannot be turned off, but I would like to hide them in the log. I tried various rules until I noticed that the broadcast packets arrive via the LAN interface (em1) to the WAN interface (em0). I don't understand this because these interfaces are physically separated.

ESXi host --> vmnic0 --> UniFi switch
ESXi host --> vmnic1 --> DrayTek Vigor 165 (modem)

Anyone have an idea what is going wrong?

Thanks in advance. Greetings.

[OPNuzz]

Can be closed. It was a vSwitch setting.

[dave]

Could you go in to a little more detail regards this setting?

I have a Unifi wap, and see these broadcasts arriving on my pppoe wan port, but never really gave them much though since they're non-routable...