I registered on this forum just to say that I've been hit with this problem too.
A restart of the radvd service fixes the problem immediately, but radvd then stops working after 24-48 hours (ipv6 solicitation stops working) until you manually restart the service.
A restart of the radvd service fixes the problem immediately, but radvd then stops working after 24-48 hours (ipv6 solicitation stops working) until you manually restart the service.