DNS (Domain Name System) is the internet’s distributed directory. It translates human-friendly domain names like example.com into the technical answers computers need to connect. Most often, this means an IP address, but DNS also handles things like email delivery and domain verification. For a more formal description, the original DNS “concepts and facilities” spec, RFC 1034, is still worth skimming.
DNS exists because the internet became too large for a single, centralized address book. Instead, DNS uses a hierarchical and delegated system. The root points to top-level domains (like .com), which then point to the authoritative nameservers for each domain. Caching helps keep lookups fast, even at a global scale, because resolvers can reuse answers until they expire instead of asking the authoritative servers every time. Without DNS, the web would be slower and less reliable.
Why DNS knowledge matters for WordPress sites
For WordPress work, DNS is the “front door.” If the domain doesn’t resolve to the right place, visitors never reach Nginx, Apache, PHP, or your caching layer. This means you might spend time troubleshooting “WordPress problems” that are actually name-resolution issues.
When you move to a new host, you usually need to change an A record (often for the root domain) and/or a CNAME (often for www). A single mistake can send traffic to an old server, cause HTTPS warnings, or create the frustrating “works for me” problem while other networks still cache old answers.
DNS changes can have side effects. If you switch nameservers or bulk-edit records, you might accidentally remove MX and TXT records that handle email, SPF/DKIM, and third-party verifications. It’s important to know where your records are stored and how to review them.
From domain names to servers: How DNS works
Translating human-friendly domains into IP addresses
DNS turns domain names into usable answers. When a browser needs your WordPress site, it usually asks for an A record (IPv4) or AAAA record (IPv6) for a hostname like www.example.com. Those records return an IP address (sometimes several), and the browser connects over HTTPS. Multiple answers can enable basic (not health-checked) load balancing and failover.
Sometimes you don’t want to publish an IP address directly. A CNAME record points one hostname to another hostname, which is useful if a provider might change the underlying IPs. The resolver follows the alias, looks up the target’s A or AAAA record, and returns the final address.
This is why many WordPress setups use A or AAAA records at the root, and a CNAME for www. DNS may seem simple at first, but it is surprisingly powerful.
What happens behind the scenes when someone visits a WordPress site
A DNS lookup usually involves more than one server, even if it feels instant. Your device has a “stub resolver” that forwards questions to a recursive resolver, the DNS service configured on your network (often your ISP, your company network, or a public resolver like 1.1.1.1 or Google Public DNS).
If the recursive resolver already has a cached answer for www.example.com, it can reply right away. If not, it follows the DNS hierarchy. It starts at the root, which points to the nameservers for the top-level domain. The root layer is served by a global system with many instances for resiliency. Next, the resolver asks the TLD nameservers (like .com or .org) which authoritative nameservers handle the domain. Finally, it queries those authoritative servers for the exact record type it needs (A, AAAA, CNAME, etc.) and caches the result for the record’s TTL. This cache timer explains why a DNS change can look inconsistent: one person sees the new site, while another still sees the old one until their resolver updates.
Once the browser has an IP address, DNS is mostly done. The browser then opens a network connection, negotiates TLS for HTTPS, and requests your WordPress pages. After that, what you see depends on hosting, caching, PHP, database performance, and front-end behavior, not DNS.
Nameservers, zone files, and DNS providers
What nameservers do
Nameservers are the DNS servers that answer questions about your domain. The important idea is authority: the authoritative nameservers for example.com are the source of truth for example.com’s records. When you “set your nameservers” at a registrar, you’re publishing an NS delegation that tells the internet where that truth lives. Most domains publish at least two NS records so there’s no single point of failure.
This is why it’s possible to edit records in the “wrong” place. You can type an A record into a DNS dashboard all day, but if the domain is delegated to different nameservers, resolvers will never see the change because they’re asking someone else.
Good authoritative DNS is built like critical infrastructure, with redundant networks, global distribution, and fast responses. If authoritative nameservers are slow or down, your WordPress host might be working, but visitors still can’t reach your domain.
Zone files and where DNS records live
A DNS zone is the part of the namespace your authoritative servers manage. This is often a single domain, but sometimes includes delegated subdomains. The zone’s data is stored in a “zone file,” which is a structured list of records (A, CNAME, MX, TXT, and others). Traditional DNS software stores this as plain text in BIND-style format, but most providers now hide the syntax behind a web interface.
Even if you never edit raw zone files, it helps to know what’s there: an SOA record for zone metadata, NS records for authority, and the record sets you change during launches and migrations.
How DNS providers and registrars fit into the picture
Your registrar is where the domain is registered. Its key DNS-related job is publishing which nameservers are authoritative for the domain (the NS delegation). Your DNS provider is where the zone is hosted and where you create and edit records.
Sometimes your registrar and DNS provider are the same company, but they don’t have to be. You can register a domain in one place and point its nameservers somewhere else for DNS management. Before you change records, always check which nameservers the domain is using, and only edit DNS at the provider that matches. This prevents changes that have no effect.
DNS record types you’ll actually use with WordPress
A records vs. CNAMEs
For WordPress, most “make my domain work” tasks come down to one decision: do you point a name to an IP address, or to another name?
A records
An A record maps a hostname to an IPv4 address. Use it when your host gives you a specific IP. It’s also the default choice for the root (apex) domain (the bare example.com) because the apex already has required records like SOA and NS.
CNAME records
A CNAME record maps a hostname to another hostname. This is ideal for www.example.com because it lets a provider change the underlying IPs without you needing to update DNS. A CNAME adds one extra lookup, but visitors usually won’t notice. The key rule is that if a CNAME exists at a name, no other record types should be there. This is why “CNAME at the apex” is generally not allowed in standard DNS.
If a platform gives you a hostname but you need the root domain to work, many DNS providers offer “apex alias” features (ALIAS/ANAME or CNAME flattening) that return A/AAAA answers to clients while you manage a hostname target internally. A common pattern is root A/AAAA (or alias) plus a CNAME for www.
Other common records: AAAA, MX, and TXT
AAAA Records
An AAAA record is the IPv6 version of an A record. If your WordPress host supports IPv6 and gives you an address, adding an AAAA record can improve connectivity on IPv6-first networks. If the host doesn’t support IPv6, don’t guess. An incorrect AAAA record can send IPv6-capable visitors to a dead end.
MX Records
MX records tell the world where to deliver email for your domain. Your website host and your email provider are often different, so MX records frequently point somewhere else entirely. This is why “I changed DNS for my site and email broke” is such a common story: a nameserver switch or a sloppy zone copy can drop MX records and stop mail flow. If you’re migrating DNS, inventory your MX records first (and consider tools like your provider’s “export zone” feature).
TXT Records
TXT records are very versatile. They are used for domain verification (like Google Search Console, SaaS onboarding, or SSL validation) and for email authentication such as SPF, DKIM, and DMARC. Many platforms ask you to “add a TXT record,” but they usually mean “add another one.” Be careful not to overwrite existing policies. Multiple TXT records can exist at once, though dashboards may display them in a confusing way.
Root domains, www, and subdomains
DNS treats example.com and www.example.com as different hostnames. They can lead to the same WordPress site, but you have to configure both. Subdomains like blog.example.com or staging.example.com are separate names too, each with its own records.
Most DNS dashboards show the root domain as @ (the “zone apex”). The apex is special because it is also where the zone’s SOA and NS records are stored, which is why a CNAME usually can’t be used there. If you want the root domain to point to a hostname, use ALIAS, ANAME, or CNAME-flattening features, then set up one main URL with redirects and WordPress settings.
Connecting DNS to WordPress hosting
Pointing a domain to a WordPress host
There are usually two ways to connect a domain to WordPress hosting. In the “change records” method, you keep your current nameservers and update the web records: set an A or AAAA record for the root domain and a CNAME (or A) for www, using the values your host gives you. This is best if you already have email, verification TXT records, or subdomains you want to keep.
In the “change nameservers” method, you delegate the entire domain to a new DNS provider. This can be convenient, but it means you are doing a DNS migration. You must recreate every record you still need, not just the website entries.
In either case, get the exact target IP or hostname from your host before making changes, and ensure you’re editing from the zone file managed by the authoritative DNS provider.
Managed hosting for WordPress and DNS expectations
Managed hosting for WordPress is designed so DNS stays simple. Most platforms give you one target: a fixed IP address (use an A record) or a canonical hostname (use a CNAME, or an apex-alias feature for the root). Behind that target may be load balancers and autoscaling.
You still need to make sure everything is consistent. Hosts usually expect both the root domain and www to resolve correctly, or for one to redirect to the other. Many platforms will not finish setting up HTTPS until DNS points to the right place. Treat DNS as part of onboarding, not something to handle later.
DNS changes that can break a WordPress site
Most DNS outages are simple mistakes with big consequences. Switching nameservers without copying the full zone can drop MX/TXT records and break email or verifications. Pointing www but not the root (or vice versa) can make a site appear randomly “down,” depending on which URL someone tries.
Caching is another common issue. After you change a record, resolvers may keep showing the old value until the TTL expires. Even “does not exist” responses can be cached for a while. Plan your cutovers with this delay in mind, and don’t turn off the old server right away.
DNS propagation, TTL, and timing expectations
Why DNS changes take time
Let’s dive into this process a bit more. “DNS propagation” is really just another term for caching. Recursive resolvers store answers so they don’t have to ask authoritative servers every time. This keeps DNS fast, but it also means different networks can see different answers for a short time after you update a record.
The record’s TTL (time to live) is the timer that controls how long an answer can be reused. For example, if an A record has a TTL of 3600 seconds, a resolver that cached the old value five minutes ago may keep returning it for up to 55 more minutes. Another resolver that never cached it will fetch the new answer right away. Negative caching works the same way: if a resolver recently got an NXDOMAIN (“doesn’t exist”), it can cache that result too.
TTL best practices
Long TTLs (hours to a day) reduce the number of queries and make repeat visits faster because answers are reused. Short TTLs (minutes) make changes take effect faster, but they increase DNS traffic and make you more dependent on how resolvers behave.
A practical approach for WordPress is to lower TTLs a day before a planned migration, make the switch, check that everything works, then raise TTLs again once things are stable. This lets you roll back quickly if needed, without keeping ultra-low TTLs all the time. Network operators often warn against using very low TTLs at internet scale.
Common DNS issues and troubleshooting for WordPress
Is this a DNS problem or a WordPress problem?
A reliable way to separate DNS issues from WordPress issues is to ask: “Can I resolve the domain to the expected endpoint?” If a lookup returns NXDOMAIN, SERVFAIL, or the wrong IP/hostname, you’re not in WordPress territory yet, fix DNS first.
If DNS resolves correctly, check the next layer. Server-side errors (500s), database connection problems, and white screens are usually related to WordPress, PHP, or hosting. Certificate warnings can be related to DNS (if you are reaching the wrong server) or to TLS configuration. DNS is not always the problem, but it is quick to check, and it must work before anything else during cutovers.
Quick tools and checks for DNS issues
When DNS feels suspicious, test it directly with dig (or nslookup). Query the record type you care about, then compare results across two resolvers to spot caching issues.
To bypass caches, query the domain’s authoritative nameservers. This shows what your DNS provider is currently serving.
- After that, check the basics:
- Do the NS records match the provider you are editing?
- Did you create a CNAME conflict?
- Did a nameserver switch remove MX or TXT records?
Oracle’s guide to testing DNS with dig is a solid reference.
Where DNS gets more advanced
Subdomains, staging, and multisite
Once you understand the basics, DNS becomes a tool for designing your environment. It’s common to use staging.example.com for QA, dev.example.com for testing, or region-based subdomains. Choose a consistent pattern (A or CNAME) and document it so your next migration is predictable.
WordPress Multisite adds another layer. Subdomain-based networks often involve wildcard DNS and a certificate plan that matches. At that point, DNS is part of the architecture, not just plumbing.
DNS performance, CDNs, and security
DNS performance shows up on first visits, when the browser must resolve names before it can fetch pages. Good DNS uses caching and globally distributed authoritative servers (often anycast) so lookups stay fast.
DNS also powers many CDNs. Changing a record can shift traffic to a different edge location without changing anything in WordPress. For security, TXT-based email authentication helps reduce spoofing, and DNSSEC adds signatures to help prevent tampering. These are worth learning once you understand the basics.
Conclusion
DNS doesn’t have to be confusing. For WordPress developers and admins, the key is having a clear mental model:
- Nameservers determine where “truth” lives.
- A/AAAA and CNAME records get browsers to your site.
- MX and TXT records keep email and third-party services working.
- TTL explains why changes can look inconsistent for a bit.
When you use this model, launches become less stressful. You know where to make changes, what to double-check before switching, and why “it’s still not working” might just be due to caching.
If you run WordPress at a large scale, DNS mistakes can be costly. They can take a site down and cause strange, region-specific problems that are hard to reproduce. This is one reason teams use managed hosting for WordPress and mature DNS tools.
DNS may not be something you think about every day, but it plays a big role in whether your WordPress site is reachable at all. When you understand how domains connect to servers, where DNS records live, and why changes take time, you can avoid many common issues before they happen. With a solid grasp of the basics, DNS becomes just another reliable part of running and maintaining WordPress sites, not a source of last-minute surprises.
