[Question] How to force IPv6 RA and IPv6 DNS settings not working?

Hello all,
EDIT: I’ve got my static ULA IPv6 set up and router advertising enabled in dnsmasq, but there is one more problem: I cannot seem to change the IPv6 DNS server that is advertised. I tried putting option6:23,[fd00:d:e:f::18] into Interface-LAN-DHCP-Advanced-DHCP options, and tried putting fd00:d:e:f::18 into Interface-LAN-DHCP-IPv6-Advertised DNS Servers. Nothing changes, it still advertises fd00:d:e:f::1 which is the router’s address, and the link-local address of the router starting with fe80. Anyone knows how to change this?

EDIT 2: it seems that RA is not handled by dnsmasq in OpenWRT so I can’t just enable-ra with dnsmasq or they would conflict. So the question is back to how do I force RA to be enabled.

Original post:
Due to my personal needs I have added a ULA prefix of fd00:d:e:f::1/64 into the LAN bridge interface of my MT1300 router manually, in order to setup static IPv6 with dnsmasq. I’ve done this with some other router firmwares (dd-wrt and merlin) and they work fine, but OpenWRT seems to only advertise IPv6 prefixes if it gets IPv6 internet connectivity. Is there a way to make the router advertise this prefix regardless so I can always have IPv6 ULAs in my network?

Thanks in advance.

Not sure if I got your scenario right, but as of today, I had to change (and enable) RAs via the script /etc/init.d/gl_ipv6