block DNS requests when VPN tunnel is down

Open collinbarrett opened this issue 5 years ago • 1 comments

To prevent ISP from snooping on dnsmasq-proxied DNS queries. NextDNS is proving that some DNS requests are made via my WAN directly outside the OpenVPN client when OpenVPN is down or restarting.

Jul 27 '20 14:07 collinbarrett

# block non-VPN DNS requests
# TODO: allow ProtonVPN server info lookup to succeed (https://collinmbarrett.com/protonvpn-dd-wrt-api-script/)
# iptables -I FORWARD -o $WAN_IF -p tcp --dport 53 -j REJECT --reject-with tcp-reset
# iptables -I FORWARD -o $WAN_IF -p udp --dport 53 -j REJECT --reject-with udp-reset
# iptables -I OUTPUT -o $WAN_IF -p tcp --dport 53 -j REJECT --reject-with tcp-reset
# iptables -I OUTPUT -o $WAN_IF -p udp --dport 53 -j REJECT --reject-with udp-reset

ref

Jul 29 '21 11:07 collinbarrett