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Glue Records

How to set up glue records so your nameservers can resolve themselves.

Last updated 1775606400

Glue records solve a bootstrapping problem: if ns1.yourhosting.com is the nameserver for yourhosting.com, how does anyone look up the IP of ns1.yourhosting.com? They'd need to ask the nameserver for yourhosting.com — which is ns1.yourhosting.com — a circular dependency.

The solution is glue records: IP addresses registered directly at the domain registrar alongside the nameserver records. Resolvers can use these to bootstrap without any circular dependency.

When You Need Glue Records

You need glue records if and only if your nameserver hostname is within the domain it's serving. Examples:

  • Needs glue: ns1.yourhosting.com serving yourhosting.com ✓ — the nameserver is under the domain
  • Needs glue: ns1.yourhosting.com serving yourhosting.com AND client domains
  • No glue needed: ns1.somethirdparty.com serving yourhosting.com — nameserver is under a different domain

For typical Opterius hosting setups (you host your own nameservers under your own domain), you need glue records.

Setting Up Glue Records

Glue records are registered at the domain registrar for the parent domain (the domain under which the nameserver lives). If your nameservers are ns1.yourhosting.com and ns2.yourhosting.com, you add glue records at the registrar for yourhosting.com.

The process varies by registrar but typically:

  1. Log in to your registrar
  2. Find "Register Nameservers," "Host Records," or "Glue Records" (terminology varies)
  3. Add entries:
    • ns1 → YOUR_SERVER_IP_1
    • ns2 → YOUR_SERVER_IP_2
  4. Save

Then separately, when registering client domains, set their nameservers to ns1.yourhosting.com and ns2.yourhosting.com.

Two IPs for Reliability

ICANN and most registrars require at least two nameservers. The two nameservers can be:

  • Same physical server, two IPs — works and is fine for small setups, but if the server goes down, DNS resolution stops for all your clients
  • Two separate servers — better reliability; one can be down without affecting DNS

For basic setups, a single server with two IPs (each configured as a separate nameserver) is acceptable. For production hosting, a secondary DNS server on different infrastructure is recommended.

Verify Glue Records Are Registered

Once set up, verify with:

# Check that your registrar has glue records for your nameserver hostnames
dig NS yourhosting.com +additional

# The "Additional section" should show A records for ns1 and ns2

Configuring Nameserver Hostnames in Opterius

Once glue records are set up at the registrar, tell Opterius what your nameserver names are:

  1. In Server Mode, go to Settings → DNS
  2. Set Nameserver 1 and Nameserver 2 to your nameserver hostnames
  3. Save

These values are used in the SOA and NS records Opterius creates for every new domain.

Next Steps

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