The following should send a mDNS query on the local network for go-ipfs instances to enable local peer discovery.
dns-sd -Q 'ipfs.local' 'PTR' 'IN'
However, this doesn’t get any responses back from any of the go-ipfs instances I have running. Not even the local machine responds. I’ve checked and double-checked that the machines have opened their firewalls to mDNS traffic. All the systems run either avahi (Linux) or bonjour (macOS); and other mDNS applications work just fine.