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

which is likely to list a lot of answers.

You can customize the queries run:

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

Minimal mDNS example

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