Description

PR #13383 fixed the unicast filtering for stm32, but at the same time blocked the filtering of multicast addresses. However, since NDP maps to a multicast address, the neighbor table remained empty, which prevented the sending of IPv6 packets.
PR #13487 then fixed this issue by reactivating the passing of all frames with a multicast address.

So far, an adequate multicast address assignment is missing in RIOT so that the stm32 has to filter for every frame containing a multicast address.

Useful links

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