How to Configure Unbound DNS Resolver on Linux

Unbound is a validating, recursive DNS resolver. Running locally reduces latency, validates DNSSEC and improves privacy.

Step 1 — Install Unbound

sudo apt install unbound -y

Step 2 — Configure

sudo nano /etc/unbound/unbound.conf.d/local.conf

server:
    interface: 127.0.0.1
    port: 5335
    auto-trust-anchor-file: "/var/lib/unbound/root.key"
    num-threads: 4
    cache-min-ttl: 3600
    hide-identity: yes
    hide-version: yes
    harden-glue: yes
    harden-dnssec-stripped: yes

Step 3 — Start and Test

sudo systemctl enable unbound --now
dig @127.0.0.1 -p 5335 google.com
# SERVFAIL for invalid DNSSEC:
dig @127.0.0.1 -p 5335 dnssec-failed.org

Conclusion

Unbound provides fast, private DNS resolution. Our team configures complete DNS infrastructure including DNSSEC validation.