How do I stop OpenWRT from advertising itself as a DNS6-server? Nothing I do seems to work, it insists on advertising itself as a DNS6-server on a IPv6 link-local address. The router is not serving DHCP, it's not supposed to be serving DNS, it's only supposed to handle routing. I already have a separate router that handles DHCP and DNS and all that and I don't want my OpenWRT-routers messing with that.
I have tried setting the OpenWRT-routers to only listen on lo - interface, I have disabled IPv6 router-advertisements, I have tried disabling DNS via the following:
uci set dhcp.@dnsmasq[0].port="0"
uci commit dhcp
/etc/init.d/dnsmasq restart
But no, nothing I do seems to stop them from advertising themselves as DNS-servers on IPv6 link-local addresses.
I just stumbled upon something that works. No idea if this is the "correct" way of doing it, but I'll leave this here in case someone else wants this as well; I had to change the settings for the 'lan' interface in /etc/config/dhcp to:
This is turning off both DHCPv4 and the RAs/DHCPv6.
If you don't want RAs (which carry also nameserver information) you can disable Router Advertisement Service and DHCPv6 Service.