Configuring DNSSEC with NSD | Configuring Zones

DNSSEC (Domain Name System Security Extensions) is a suite of specifications that add a layer of security to the DNS system, helping to prevent DNS spoofing and other attacks. NSD (Name Server Daemon) is a popular, open-source DNS server implementation that supports DNSSEC.

Prerequisites:

• A running NSD instance.
• A DNS zone file for the domain you want to enable DNSSEC for.
• A key pair (private and public keys) generated using a tool like dnssec-keygen.

Steps to Configure DNSSEC with NSD:

• Create a DNSSEC zone:

Add the following lines to your DNS zone file:
key example.com. DS 256 3 5 12345678901234567890123456789012345678901234567890
key example.com. KSK 256 3 5 12345678901234567890123456789012345678901234567890

• Replace the placeholder key values with the actual values from your key pair.

Add the following line to the zone’s control section:
controls {

  allow-update { key example.com.; };

};

• Create a zone file for the keys:
  Create a new zone file for the keys (e.g., keys.example.com).

Add the following lines:
key example.com. 256 3 5 12345678901234567890123456789012345678901234567890 13
key example.com. 256 3 5 12345678901234567890123456789012345678901234567890 13

• Replace the placeholder key values with the actual values from your key pair.

• Configure NSD to use the keys:
  
• In your NSD configuration file, add the following lines:
• zone “example.com” {
•   type master;
•   file “/etc/bind/example.com”;
•   allow-update { key example.com.; };
•   dnssec-validation yes;
•   key-directory “/etc/bind/keys”;
• };

• Replace the paths with the actual paths to your zone files and key directory.

• Generate the DS record:

Use the dnssec-signzone tool to generate the DS record for your zone:
dnssec-signzone -e example.com. -k keys.example.com. -o example.com.db

• Add the generated DS record to your main zone file.

• Restart NSD:
  • Restart the NSD service to apply the changes.
• Verify DNSSEC:
  Use a DNS lookup tool like dig to verify that the DNSSEC signatures are being generated and validated correctly.

Note: This is a basic example. For more complex setups, you may need to configure additional settings, such as key rollovers and delegation. It’s recommended to consult the NSD documentation for more detailed information.