Captive portal causing Sendto permission denied errors with udpbroadcastrelay

[bitrot]

I've been trying to get my Sonos system to work properly across an IoT VLAN using udpbroadcastrelay as described in this thread: https://forum.netgate.com/topic/155698/how-can-i-get-this-udp-relay-package-for-casting-across-vlans

@jimp I couldn't get discovery to work correctly and found your response in another thread (https://forum.netgate.com/post/888663) while troubleshooting because I was getting "Sendto permission denied" errors when running the udpbroadcastrelay command. When I turn off captive portal, these errors go away and Sonos discovery works correctly. But I have no idea what about captive portal is causing this.

Below is my captive portal configuration:

Known devices are configured on the MAC's tab

[jimp]

Captive portal by design blocks L2 communication and up, which is also blocking multicast. It only allows a small number of things in L2 by default (ARP, PPPoE, and a couple other similar things).

In addition to the known devices you'll also have to add bypasses for whatever multicast destinations you want to allow, though I haven't tested that. It may work, but I wouldn't expect much from trying to allow all that on a segment with captive portal. Might be best to put that on a separate VLAN that doesn't have that in place.

[bitrot]

Thanks @jimp

Adding an "Allowed IP Address" of 239.255.255.250 for SSDP (Roku Discovery, DLNA Media, Sonos, UPnP + More) to the captive portal did the trick. Thanks a bunch

I've also added 224.0.0.251 for mDNS / Multicast DNS (Chromecast Discovery + Bonjour + More)

Works like a charm now :)