DoT with Unbound

This article relies on the following:

Introduction

  • This how-to describes the method for setting up DNS over TLS on OpenWrt.
  • It relies on Unbound for performance and fault tolerance.
  • Follow DNS hijacking to intercept DNS traffic or use VPN to protect all traffic.

Goals

  • Encrypt your DNS traffic improving security and privacy.
    • Prevent DNS leak and DNS hijacking.
  • Bypass regional restrictions using public DNS providers.
    • Escape DNS-based content filters and internet censorship.

Command-line instructions

Disable Dnsmasq DNS role or remove it completely optionally replacing its DHCP role with odhcpd.

Install the required packages. Enable DNS encryption. 

# Install packages
opkg update
opkg install unbound-daemon
 
# Enable DNS encryption
uci set unbound.fwd_google.enabled="1"
uci set unbound.fwd_google.fallback="0"
uci commit unbound
/etc/init.d/unbound restart

LAN clients and local system should use Unbound as a primary resolver assuming that Dnsmasq is disabled.

Testing

Use nslookup to verify that domain name resolution works. 

nslookup openwrt.org localhost

Check your DNS provider. Make sure there is no DNS leak.

Test DNSSEC validation.

Troubleshooting

Collect and analyze the following information. 

# Restart services
/etc/init.d/log restart; /etc/init.d/unbound restart
 
# Log and status
logread -e unbound; netstat -l -n -p | grep -e unbound
 
# Runtime configuration
pgrep -f -a unbound
head -v -n -0 /etc/resolv.* /tmp/resolv.* /tmp/resolv.*/*
 
# Persistent configuration
uci show unbound

Extras

Web interface

If you want to manage the settings using web interface. Install the necessary packages. 

# Install packages
opkg update
opkg install luci-app-unbound
/etc/init.d/rpcd restart

Navigate to LuCI → Services → Recursive DNS to configure Unbound.

DoT provider

Unbound is configured with Google DNS. You can change it to Cloudflare DNS or any other DoT provider including your own DoT server with Nginx. Use resolvers supporting DNSSEC validation if necessary. Specify several resolvers to improve fault tolerance.

Change to Cloudflare DNS 

# Configure DoT provider
uci set unbound.fwd_google.enabled="0"
uci set unbound.fwd_cloudflare.enabled="1"
uci set unbound.fwd_cloudflare.fallback="0"
uci commit unbound
/etc/init.d/unbound restart

Change to other DoT provider 

# Configure DoT provider (example: "Cloudflare Family Protection")
uci set unbound.fwd_google.enabled="0"
uci set unbound.fwd_cloudflare.enabled="0"
while uci -q delete unbound.@zone[4]; do :; done
uci add unbound zone
uci set unbound.@zone[-1].enabled="1"
uci set unbound.@zone[-1].fallback="0"
uci set unbound.@zone[-1].zone_type="forward_zone"
uci add_list unbound.@zone[-1].zone_name="."
uci set unbound.@zone[-1].tls_upstream="1"
uci set unbound.@zone[-1].tls_index="family.cloudflare-dns.com"
uci add_list unbound.@zone[-1].server="1.1.1.3"
uci add_list unbound.@zone[-1].server="1.0.0.3"
uci add_list unbound.@zone[-1].server="2606:4700:4700::1113"
uci add_list unbound.@zone[-1].server="2606:4700:4700::1003"
uci commit unbound
/etc/init.d/unbound restart

DNSSEC validation

Enforce DNSSEC validation if your DNS provider does not support it, or you want to perform the validation yourself. Beware of fault tolerance and performance issues. 

# Enforce DNSSEC validation
uci set unbound.@unbound[0].validator="1"
uci commit unbound
/etc/init.d/unbound restart
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  • Last modified: 2022/04/23 04:54
  • by lastedit