I have a VPN connecting two virtual interfaces of two hosts. Both VPN interfaces have MAC addresses 00:00:00:00:00:00, as the OS (Linux) assigns link-local IPv6 address based on MAC address. So the link-local IPv6 addresses are identical for both peers. This breaks OSPFv3 (at least).
What is the right way to obtain IPv6 addresses, which would be unique on the link, for such interfaces? I expect that I'd not need to configure a new IPv6 network and manually assign addresses from it to VPN endpoints.