I want to use .lan as TLD for the entire network (which is OpenWRT's default behaviour), and create .eon.lan subnet for my room network. Devices in both area should be able to talk to each other. This requires configuring DNS and static routes.
Network > DHCP and DNS > General Settings tab./eon.lan/192.168.1.2 to DNS forwardingeon.lan to Domain whitelist.
(This option appears only when Rebind protection is on.)Local Service Only
(You might want to add WAN to Exclude interfaces. e.g. eth1.2)Network > Static RoutesNetwork > DHCP and DNS > General Settings tab.Local server to /eon.lan/Local domain to eon.lanLocal Service Onlylan to Domain whitelist.
(This option appears only when Rebind protection is on.)192.168.1.1 to DNS forwardings.