How to enable multicast DNS (RFC 6762)?

[Asperamanca]

How do I enable multicast DNS within my local network?
I have not found anything about mDns in the unbound DNS documentation. There is documentation about a multicast dns proxy, but all my devices are in the same VLAN, so that should not be necessary.
I already use unbound DNS with DHCP leases registered.

My symptoms are that Android and Kodi devices have issues discovering other devices in my local network, where a port scanner app can clearly show the device to be accessible. A vendor pointed me to mDNS as requirement for discovery of their sound equipment.

[chemlud]

Maybe?

https://forum.opnsense.org/index.php?topic=5865.0

[Asperamanca]

As mentioned, I don't need a proxy between interfaces. I need mDNS to work within one interface. So I didn't see how the linked post could help me...?

[chemlud]

For multicast on a single LAN the OPNsense is not needed at all, that's what mDNS was designed for imho...

[Patrick M. Hausen]

He probably wants the OPNsense to announce itself properly. I'd really like that, too. I run avahi-app in all my FreeBSD jails and the ssh config tells ssh that if I do e.g. ˋssh gitea.localˋ, just use the root account and private key, thank you.
ˋPermitRootLogin prohibit-passwordˋ on a private LAN - perfectly reasonable, IMHO.

[Asperamanca]

For multicast on a single LAN the OPNsense is not needed at all, that's what mDNS was designed for imho...

You are right. I obviously misunderstood how mDNS works. The devices should take care of exchanging information by themselves, using broadcast, right?
Any advice how I get started analyzing broadcast issues in my network? (I am aware that this is outside OPNsense now...or can OPNsense help me trace the issue?)

[Patrick M. Hausen]

If you are on a Mac, this is my favourite tool to check mDNS:
https://www.macupdate.com/app/mac/13388/discovery

[chemlud]

For multicast on a single LAN the OPNsense is not needed at all, that's what mDNS was designed for imho...

You are right. I obviously misunderstood how mDNS works. The devices should take care of exchanging information by themselves, using broadcast, right?
Any advice how I get started analyzing broadcast issues in my network? (I am aware that this is outside OPNsense now...or can OPNsense help me trace the issue?)

Package capture on the LAN interface, UDP port 5353

https://osqa-ask.wireshark.org/questions/34456/capturing-mdns-packet

[Asperamanca]

I can see mDNS requests sent via Wireshark (e.g. triggered by VLC), but I cannot see any answer although there should be multiple devices responding.
Should I see answers using filter "udp port 5353"?

Since both requester and responder are on the same switch, I guess this means that the switch somehow blocks the requests or replies?

[Asperamanca]

OK, someone at UniFi thought "Multicast and Broadcast Filtering" would make a great default option for a Wifi AP. I must have overlooked that at initial setup.

Case closed. Thanks for the help!