DNS 보안 기능 추가

기본 구성

Router

vi /etc/netplan/50-cloud-init.yaml

netplan generate
netplan apply

vi /etc/sysctl.conf

sysctl -p

iptables -A POSTROUTING -t nat -o enp0s9 -j MASQUERADE

Client

vi /etc/netplan/50-cloud-init.yaml

netplan generate
netplan apply