Create /jffs/configs/dnsmasq.conf.add
and add DHCP option 119
providing the domain search list (home
in the example below):
dhcp-option=lan,119,home
Allow custom configs in the nvram:
nvram set jffs2_scripts=1
Restart dnsmasq:
service restart_dnsmasq
Check that dnsmasq config contains new option:
grep 'dhcp-option=lan,119,home' /etc/dnsmasq.conf || echo "Error! Option has not been added!"
The above has been tested on the Asus RT-AC66U with ASUSWRT-Merlin RT-AC66U_3.0.0.4