UDP broadcasts across subnets


I have a Unifi Security Gateway as my router & firewall. I have a Weewx VM running on VLAN 1 ( and my Weatherflow Hub is on VLAN 2 ( I have my firewall rules set up so that my Weewx VM can reach the Hub (i.e via ping), but unfortunately it seems like it can’t pick up the UDP broadcasts the Hub is sending out on VLAN 2.

I was wondering what the best way of making that happen would be? Other than moving the Hub or VM into the same VLAN. Any advice?

The broadcasts will not span broadcast domains (VLANs). You will need to move one or the other into the same VLAN.

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Add a second network interface to the VM on VLAN 2???


I totally forgot I could do that. Simple and easy. It worked. Thank you!

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remember though - having a dual-homed system kinda mitigates the value of VLANing your LAN. I would firewall the heck out of it and only permit udp/50222 in, and be very careful so your VM doesn’t act as a router.


Yeah, I ended up just removing the VLAN 1 vNIC and keeping the VLAN 2 NIC, so it’s on the same VLAN as the WF hub and nothing else. My firewall permits udp/50222 so I think we’re good!