MLD Snooping will cause the NDP Proxy to fail. We need the MLD Proxy.

[theoryfate]

By monitoring the MLD report, MLD Snooping constructs a mapping table from the multicast address to the switch port to prevent multicast packets from being broadcast on the Layer 2 network.

This is a disaster for the NDP Proxy!

Because the multicast neighbor discovery request (ff02::1:ffxx:xxxx/104) will only be forwarded to the port that has sent the MLD report, and will not be sent to the host where the NDP Proxy is running, this is not a broadcast.

The neighbor discovery request for the internal network host address is not sent to the host where the NDP Proxy is running, because the MLD report sent by the internal network host cannot reach the switch of the external network.

So we need a function to forward the MLD report of the internal network to the external network, so that MLD Snooping of the external switch knows that we are interested in these multicast addresses. This is the MLD Proxy.

Without MLD Proxy, NDP Proxy projects will become useless as more and more switches use MLD Snooping to reduce multicast traffic performance overhead.

[nihilus]

This is a known issue, not even the Linux kernel's built-in ND proxy support doesn't work correctly as per one would suppose.

What I think is your issue is that the DAD / NA stuff is not working correctly.