Minimal mDNS example

This example demonstrates the multicast DNS (mDNS) protocol functionality in Matter.

Example server

The file server.cpp contains an example of a mdns server that can listen on both IPv4 and IPv6 interfaces or mDNS queries.

To run, you can use:

./out/minimal_mdns/minimal-mdns-server -4

which will listen on both IPv4 and IPv6 addresses, on port 5353.

See

./out/minimal_mdns/minimal-mdns-server --help

for supported options.

The server will print out any queries as well as any advertisements it sees on the network while running.

Example client

The file client.cpp contains an example of a mdns client. By default it queries for _services._dns-sd._udp.local (DNS-SD list services) and uses unicast queries.

Example run:

./out/minimal_mdns/minimal-mdns-client -4

which is likely to list a lot of answers.

You can customize the queries run:

/out/minimal_mdns/minimal-mdns-client -4 -q chip-mdns-demo._matter._tcp.local

see

./out/minimal_mdns/minimal-mdns-client --help

for full command line details.

Example advertiser

This example uses the chip built-in advertiser, implemented in the file advertiser.cpp.

Example runs:

./out/minimal_mdns/mdns-advertiser -4 -m operational

./out/minimal_mdns/mdns-advertiser -4 -m commissionable-node --vendor-id 123 --product-id 456

./out/minimal_mdns/mdns-advertiser -4 -m commissioner --vendor-id 123 --product-id 456 --device-type 35

see

./out/minimal_mdns/mdns-advertiser --help

for full command line details.

Testing with dns-sd

If you have a mac computer (or are able to install dns-sd via opkg), here are some helpful examples on usage. More details are available in the CHIP spec on discovery.

Advertising to test client listings

Simulated uncommissioned node

dns-sd -R DD200C20D25AE5F7 _matterc._udp,S52,L840,V123 . 11111 D=840 VP=123+456

Will create the following records

_matterc._udp.local.                   PTR   DD200C20D25AE5F7._matterc._udp.local.
S52._sub._matterc._udp.local.          PTR   DD200C20D25AE5F7._matterc._udp.local.
L840._sub._matterc._udp.local.         PTR   DD200C20D25AE5F7._matterc._udp.local.
V123._sub._matterc._udp.local.         PTR   DD200C20D25AE5F7._matterc._udp.local.
DD200C20D25AE5F7._matterc._udp.local.  TXT   "D=840" "VP=123+456"
DD200C20D25AE5F7._matterc._udp.local.  SRV   0 0 11111 B75AFB458ECD.local.
B75AFB458ECD.local.                  AAAA  ba2a:b311:742e:b44c:f515:576f:9783:3f30

Simulated commissioning node

dns-sd -R DD200C20D25AE5F7 _matterd._udp,S52,L840,V123 . 11111 D=840 VP=123+456 PH=3

Will create the following records:

_matterd._udp.local.                   PTR   DD200C20D25AE5F7._matterd._udp.local.
S52._sub._matterd._udp.local.          PTR   DD200C20D25AE5F7._matterd._udp.local.
V123._sub._matterd._udp.local.         PTR   DD200C20D25AE5F7._matterd._udp.local.
D840._sub._matterd._udp.local.         PTR   DD200C20D25AE5F7._matterd._udp.local.
DD200C20D25AE5F7._matterd._udp.local.  TXT   "D=840" "VP=123+456" "PH=3"
DD200C20D25AE5F7._matterd._udp.local.  SRV   0 0 11111 B75AFB458ECD.local.
B75AFB458ECD.local.                    AAAA  ba2a:b311:742e:b44c:f515:576f:9783:3f30

Simulated commissioned node

dns-sd -R 2906C908D115D362-8FC7772401CD0696 _matter._tcp . 22222

Discovery commands

Nodes:

dns-sd -B _matterc._udp         # Nodes awaiting commissioning
dns-sd -B _matterc._udp,S52     # Nodes awaiting commissioning with short discriminator 52
dns-sd -B _matterc._udp,L840    # Nodes awaiting commissioning with long discriminator 840
dns-sd -B _matterc._udp,V123    # Nodes awaiting commissioning with vendor id 123

dns-sd -B _matterd._udp         # Commissionable nodes
dns-sd -B _matterd._udp,S52     # Commissionable nodes with short discriminator 52
dns-sd -B _matterd._udp,L840    # Commissionable nodes with long discriminator 840
dns-sd -B _matterd._udp,V123    # Commissionable nodes with vendor id 123

IP Address:

dns-sd -L 2906C908D115D362-8FC7772401CD0696 _matter._tcp  # find server address
dns-sd -Gv6 B75AFB458ECD.local                            # get IPv6 address