From a clean installation of the firmware linked above, and with the hardware connected like the diagram above shows, I am now trying to follow this post: Blocking websites on your router to implement some basic access controls. My basic goal to start is to block youtube, and the next step would be to target that to only specific devices.
However, twice now I've followed that guide and it has left things just basically broken, DHCP not working and internet access not working. I've narrowed it down to what seems like a very innocent change:
4. Set up the list of domains to block using dnsmasq
In your/etc/dnsmasq.conffile, add the following:cache-size=10000 min-cache-ttl=3600 max-cache-ttl=7200
After this I do service firewall restart and service dnsmasq restart. Then from the green PC I'm using to configure the router, it looks like I do not get an IPv4 address assigned, but do get an IPv6 address assigned. At that point I can't reach 192.168.1.1 from the PC. If I manually configure an IPv4 in range like 192.168.1.50, then I can. But no internet access.
Why would changing these cache settings affect DHCP and internet access? It looks to me like these are just changing how long DNS entries are cached for.
Is there a way to check what the default values of these config settings are with uci or some other way? I couldn't quite figure it out from what this page https://openwrt.org/docs/guide-user/base-system/dhcp.dnsmasq#etcdnsmasqconf describes but I think it must be possible.