Domains & DNS foundation

The self-paced shape of the three courses, the spine that runs through them, and how the final quiz gates progress.

Keep a running list of the bits that did not click, so they do not slip away between sittings or block you mid-lesson.

The 95% scope you will handle unsupervised, the 5% that escalates by default, and the two-question test that keeps the line honest in real time.

Registrar, DNS host, web host, mail host are four separate services, often four separate companies. Identifying which layer a ticket lives on is the cheapest mistake you can avoid in this course.

The three-party chain that holds a domain in place, the reseller-registrar pattern common in MSP work, and the support queues that go with each.

Registrant, admin, tech, billing roles, and the three contact-related bugs that bite MSPs over and over.

What WHOIS privacy hides, what it does not, and the GDPR redaction reality that already does a lot of the work for free on common gTLDs.

Read the lifecycle stage from WHOIS status flags and dates, and know which stages you can act on and which you escalate.

The two anti-theft mechanisms that keep a domain from being transferred away without the registrant's knowledge, and the pre-flight sequence that makes outbound transfers stick.

The mature original gTLDs, the post-2013 new-gTLD landscape, and the look-before-you-leap check before recommending a name for a client's primary brand.

The four-dimensional model for any ccTLD registry, plus the five-step workflow you run on each new ccTLD before quoting a client.

How to check whether a domain is available in five seconds, what WHOIS / RDAP actually returns, and why REDACTED is normal.

The four-server chain a DNS query touches, and which step the MSP actually controls.

A maps a name to IPv4; AAAA does the same for IPv6. When the two disagree, the site is half-broken for the IPv4 vs IPv6 split of users.

A pointer record with two firm rules that trip techs up: no CNAME at the apex, and a CNAME cannot share a name with other records.

Lower priority means preferred (the universal trap). MX targets must be hostnames, never CNAMEs or IPs. The canonical mail-migration sequence.

The general-purpose record. Two rules that trip techs up: multiple TXTs on a name are additive, and a single string caps at 255 characters.

TTL is the cache lifetime for a record. It shapes how long old values persist after a change, not how fast new ones propagate.

Propagation is the time old caches take to expire across downstream resolvers, not data being copied between servers. Replace the "24 to 48 hours" stock answer with a calibrated one.

The standard record set you expect on a typical small-business zone, and the omissions that flag a routine domain audit's most common findings.