redirecionar consultas dns

iptables -t nat -A PREROUTING -i ethX -p udp --dport 53 -j DNAT --to $(get lan_ipaddr)
iptables -t nat -A PREROUTING -i ethX -p tcp --dport 53 -j DNAT --to $(get lan_ipaddr)
iptables -t nat -L -v -n # shows nat table

melhor:
iptables -t nat -A PREROUTING -s 10.0.100.0/24 -p udp --dport 53 -j DNAT --to 9.9.9.9:53
iptables -t nat -A PREROUTING -s 10.0.100.0/24 -p tcp --dport 53 -j DNAT --to 9.9.9.9:53

Subscrever dns