esp-who/components/mdns/tests/host_test/README.md

Setup dummy network interfaces

Note: Set two addresses so we could use one as source and another as destination

sudo ip link add eth2 type dummy
sudo ip addr add 192.168.1.200/24 dev eth2
sudo ip addr add 192.168.1.201/24 dev eth2
sudo ip link set eth2 up
sudo ifconfig eth2 multicast

Dig on a specified interface

dig +short -b 192.168.1.200 -p 5353 @224.0.0.251 myesp.local

or a reverse query:

dig +short -b 192.168.2.200 -p 5353 @224.0.0.251 -x 192.168.1.200

Run avahi to browse services

Avahi needs the netif to have the "multicast" flag set

david@david-comp:~/esp/idf (feature/mdns_networking_socket)$ avahi-browse -a -r -p
+;eth2;IPv6;myesp-service2;Web Site;local
+;eth2;IPv4;myesp-service2;Web Site;local
=;eth2;IPv6;myesp-service2;Web Site;local;myesp.local;192.168.1.200;80;"board=esp32" "u=user" "p=password"
=;eth2;IPv4;myesp-service2;Web Site;local;myesp.local;192.168.1.200;80;"board=esp32" "u=user" "p=password"