Chapter 5

Registrars, Nameservers & Zones

Who controls what — and where to edit records.

Learning objectives

  • Map registrar, nameserver, and zone file to real control panels
  • Change nameservers without losing the domain
  • Know where to edit records vs where to renew the domain

Three layers of control

1. Registrar

ICANN/CIRA-facing record of who owns workshopco.ca. You renew here. You set which nameservers the world should use.

2. Authoritative DNS (nameservers)

Answers queries for your zone. NS records in the parent (.ca) point here. You edit A, MX, TXT records here.

3. Services (web, mail)

Servers at the IPs your DNS points to. Changing hosts means updating DNS — not necessarily transferring the domain.

Worked example — moving DNS to a new host

Workshop Co. keeps their domain at Registrar A but moves website DNS management to Swift Host:

  1. Swift Host creates a zone for workshopco.ca with all records.
  2. Swift Host provides nameservers: ns1.swifthost.ca, ns2.swifthost.ca.
  3. At Registrar A, replace old NS with the new pair. Save.
  4. Wait for propagation (Chapter 6). Verify with dig NS workshopco.ca.
Before you switch NS

Copy every existing record — especially MX and TXT for email. Missing MX after an NS change is the #1 cause of “our mail stopped working after we moved hosts.”

Glue records

If your nameservers are ns1.workshopco.ca (inside the same domain), the parent registry needs glue A records at the registrar. Most small sites use provider nameservers (ns*.provider.net) to avoid this.

Try it yourself

Look up NS records for a domain you manage (or swifthost.ca):

dig NS swifthost.ca +short
  1. Write the nameserver hostnames.
  2. Are they on the same brand as the website host, the registrar, or a third party (Cloudflare, etc.)?
  3. Where would you log in to add a new TXT record?
Guidance

You edit TXT at whoever hosts the authoritative zone — the operator of those NS hostnames. The registrar only holds NS delegations unless they also host DNS.

Check your understanding

  1. Can you transfer web hosts without transferring the domain registrar?
  2. Who publishes the NS records for workshopco.ca to the internet — the registrar or the authoritative DNS?
Answers
  1. Yes — update A/CNAME (and verify MX/TXT) at the DNS host.
  2. The .ca registry holds delegation based on what the registrar submits. The authoritative DNS must match those NS names.