External Network Cannot Discover Devices on Thread Network via mDNS

[dsyx]

I am experiencing an issue where devices within the Thread network cannot be discovered by external networks using mDNS. Below are the details regarding my OTBR build command and the outputs from the relevant commands.

OTBR Build Command:

sudo INFRA_IF_NAME=eth0 \
     RELEASE=1 REFERENCE_DEVICE=1 BACKBONE_ROUTER=1 BORDER_ROUTING=1 WEB_GUI=1 \
     OTBR_OPTIONS="-DOT_THREAD_VERSION=1.3 \
                   -DOT_POSIX_RCP_SPI_BUS=ON \
                   -DOT_PLATFORM_CONFIG=openthread-core-silabs-posix-config.h \
                   -DOTBR_DUA_ROUTING=ON -DOTBR_DNSSD_DISCOVERY_PROXY=ON -DOTBR_SRP_ADVERTISING_PROXY=ON" \
    ./script/setup

Output from ot-ctl srp server service:

MGM240_3425B4FFFE31F455._prv._tcp.default.service.arpa.
    deleted: false
    subtypes: (null)
    port: 10250
    priority: 0
    weight: 0
    ttl: 7200
    lease: 7200
    key-lease: 680400
    TXT: [EUI64=33343235423446464645333146343535]
    host: MGM240_3425B4FFFE31F455.default.service.arpa.
    addresses: [fd0f:211:2328:1:1f19:c502:101:f961]

MGM240_3425B4FFFE0E86D9._prv._tcp.default.service.arpa.
    deleted: false
    subtypes: (null)
    port: 10250
    priority: 0
    weight: 0
    ttl: 7200
    lease: 7200
    key-lease: 680400
    TXT: [EUI64=33343235423446464645304538364439]
    host: MGM240_3425B4FFFE0E86D9.default.service.arpa.
    addresses: [fd0f:211:2328:1:ddee:38f1:1bfe:8b14]
Done

Despite the above configurations, when I try to ping the device using the command ping MGM240_3425B4FFFE0E86D9.local, I receive the following error:

ping: MGM240_3425B4FFFE0E86D9.local: Name or service not known

Thanks

[jwhui]

Does your ping command support IPv6? Depending on your system, you may need to add -6 or use ping6.

You may also find the OpenThread Border Router guide useful. Specifically, the steps:

• Discover the Service
• Ping the End Device

[dsyx]

Hi @jwhui ,

The ping command supports ipv6, because pinging the ipv6 address directly is normal. Even when I use avahi-browse on the OTBR host, I can't find any Thread related services.

In addition to OTBR_DNSSD_DISCOVERY_PROXY and OTBR_SRP_ADVERTISING_PROXY, what other macros control the mDNS and SRP behavior of OTBR?

There is also a strange phenomenon: using a Linux host, you can directly ping the Thread device's ipv6 address, but the Windows host cannot ping. They are all in the same LAN (no subnet).

Thanks

[dsyx]

Refer to Ping the hostname or IPv6 address, add mdns6_minimal to /etc/nsswitch.conf and restart the machine. Now the ping command can find the appropriate IPv6 address through the mDNS domain name.

But the windows machine still cannot ping the Thread device.