Advanced DNS Security: Protecting Your Infrastructure

Advanced DNS Security Measures

This guide covers advanced DNS security measures to protect your infrastructure from sophisticated attacks.

1. DNS Firewalling

Implement DNS firewalling to block malicious domains and prevent data exfiltration:

• Use DNS filtering services (e.g., OpenDNS, Quad9)
• Configure response policy zones (RPZ)
• Block known malicious domains and IPs

2. DNS over HTTPS (DoH) and DNS over TLS (DoT)

Encrypt DNS queries to prevent eavesdropping and manipulation:

# Example DoH configuration for Unbound
do-https-forwarding: yes
forward-zone:
  name: "."
  forward-addr: 1.1.1.1@853#cloudflare-dns.com
  forward-addr: 1.0.0.1@853#cloudflare-dns.com
  forward-tls-upstream: yes

3. Rate Limiting

Protect against DNS amplification and DDoS attacks:

# BIND9 rate limiting
rate-limit {
    responses-per-second 10;
    window 5;
    qps-scale 250;
    min-table-size 500;
    min-cache-ttl 300;
};

4. Response Rate Limiting (RRL)

Mitigate DNS amplification attacks by limiting response rates:

# BIND9 RRL configuration
rrl-zone {
    zone "dns-rrl" rate-limit 20 responses-per-second max-table-size 1000000;
};

zone "example.com" {
    type master;
    file "db.example.com";
    rrl-zone "dns-rrl";
};

5. Threat Intelligence Integration

Enhance security with threat intelligence feeds:

• Subscribe to threat intelligence services
• Automatically update blocklists
• Integrate with SIEM systems