What I have here is an NTP server (on Linux Mint) and a client (likewise). Server is configured to send a multicast message across the LAN which clients receive and update their clocks - it was designed so to reduce network load.
The NTP server is, in turn, updating its own clock from a unicast NTP server of a higher level, also in the same LAN. What does not work is the receiving the multicast packet and updating clock on the client's side.
I am currently sniffing packets on the client machine and I can see multicasts coming. Using ntpdate -s on a client machine and pointing to the higher-level NTP in the same LAN works, i.e. the clock is updated.
I'm attaching configs for both Multicast server:
Here's proof that the Mcast packets reach the client:
I already tried running ntpd client with -Ab (accepting unauthenticated broadcasts), but that does not work either.
Thanks in advance for your help.