Bonjour Conformance Test - SRV PROBING/ANNOUNCEMENTS

Question

jp-developer OP

Created Jan ’25

Replies 2

Boosts 0

Participants 2

Hello,

We are currently working on a zero-configuration networking compliant device thru avahi-daemon (for mDNS/DNS-SD handling) and avahi-autoipd (for link-local address configuration).

Our test environment setup is:

Device Under Test (DUT): Debian 9 Linux
- avahi-daemon: v0.6.32
- avahi-autoipd: v0.6.32
Test Bed: Macmini with macOS Sequoia 15.0
- Bonjour Conformance Test v1.5.4
Router: NEC Aterm WR8370N
- Devices are connected via LAN

SRV PROBING/ANNOUNCEMENTS BASIC test failure was encountered in BCT during Multicast-DNS test suite execution.

Please see the logs below:

ERROR   2025-01-15 19:36:35.792930+0900: Cache flush bit is set in the SRV probes
NOTICE  2025-01-15 19:36:35.792946+0900: DEVICE-sERvICE-32\._uSCaNs\._tcp\.lOcaL\.._uscAnS._tCP.loCAL., SEND_CONFLICT_WIN -> SEND_CONFLICT_WIN
FAILED (SRV PROBING/ANNOUNCEMENTS BASIC)

START (SRV PROBING/ANNOUNCEMENTS)
DEBUG_2 2025-01-15 19:36:35.792979+0900: received packet (1137 bytes)
DEBUG_2 2025-01-15 19:36:35.792999+0900: srv_cf_probe 
WARNING 2025-01-15 19:36:35.793022+0900: SRV Probing/Announcements Failed: See runtime output for PROBING and WINNING SIMULTANEOUS PROBE for details.
FAILED (SRV PROBING/ANNOUNCEMENTS)

We would like to know what causes the above test to fail, is it related to avahi or a an inccorect mDNS service handling wherein the cache flush bit was incorrectly set?

Thank you.

Answered by jp-developer in 822266022

Hi Kevin,

Thank you for very much for checking and providing some information regarding this matter.

From further checking, it seems the SRV PROBING test failure we encountered is related to some misconfiguration or issue in Avahi. We were able to pass this test once we applied the following updates:

Remove the "%h" wildcard from the DNS-SD name
Advertise only one DNS-SD service

For now, we think it is better to consult the Avahi project in order to understand the above limitation.

Thank you.

Boost

Answer 1

DTS Engineer OP

Apple

Jan ’25

We would like to know what causes the above test to fail,

I'd need to see more of the log to get clearer context, but the error here is pretty straight forward:

ERROR   2025-01-15 19:36:35.792930+0900: Cache flush bit is set in the SRV probes

You can read more about the "cache-flush" bit in RFC-6762 <https://www.rfc-editor.org/rfc/rfc6762>, but my recollection is that "cache-flush" should not be set in basic SRV probes.

is it related to avahi or a an inccorect mDNS service handling wherein the cache flush bit was incorrectly set?

You can look at a packet trace to confirm the bits being set but I suspect something wrong with how Avahi is configured or how you're calling into it.

__
Kevin Elliott
DTS Engineer, CoreOS/Hardware

0

Answer 2

jp-developer OP

Jan ’25

Accepted Answer

Hi Kevin,

Thank you for very much for checking and providing some information regarding this matter.

From further checking, it seems the SRV PROBING test failure we encountered is related to some misconfiguration or issue in Avahi. We were able to pass this test once we applied the following updates:

Remove the "%h" wildcard from the DNS-SD name
Advertise only one DNS-SD service

For now, we think it is better to consult the Avahi project in order to understand the above limitation.

Thank you.

0