It used to be possible to clone an IPaddr2 resource for load-sharing purposes, using multicast MAC and the clusterip capability of iptables, which is now obsolete. It would be helpful to have a new resource agent for the same purpose that would set up firewall filters.
Earlier suggestions: handle IPv4 or IPv6; support common firewall back-ends; ensure network traffic correctness such as properly mangled ARP packets; communicate with firewalld over DBus instead of external commands where possible.
The idea came from the users list: