# What is a DNS A Record: Understanding the Fundamentals

> DNS A records explained: how they map domains to IPv4 addresses, how to create and check them, TTL, and how they differ from CNAME and AAAA records.

A DNS **A record** ("Address" record) maps a hostname to an IPv4 address. It is the record that turns a name people can remember, like `example.com`, into the `203.0.113.10`-style number a browser actually connects to. Every website you reach by name relies on an A record somewhere in the chain.

A records live inside the [Domain Name System](/learning/what-is-a-dns), the distributed directory that resolves names to addresses across the internet. The A record is one of the oldest and most fundamental record types in DNS, and understanding it is the foundation for everything else — including the [TXT records](/learning/what-is-a-txt-record) that carry SPF and DKIM, and the [MX records](/learning/what-is-an-mx-record) that route your mail.

## What a DNS A record does

When someone types your domain into a browser, their resolver walks the DNS hierarchy until it finds the authoritative server for your domain, then reads the A record to learn which IPv4 address hosts the site. The browser opens a connection to that address and loads the page. Without a correct A record, the name simply does not resolve and the site is unreachable — even if the server behind it is running perfectly.

A records only hold IPv4 addresses (the four-number format like `203.0.113.10`). The IPv6 equivalent is the [AAAA record](/learning/what-is-an-aaaa-dns-record-quad-a-explained), which does the same job for longer 128-bit addresses. Many domains publish both so that clients on either network can connect.

## DNS A record syntax

In a zone file, an A record follows this structure:

```
example.com.    3600    IN    A    203.0.113.10
```

Each field has a specific role:

- **`example.com.`** — the hostname the record answers for. The trailing dot marks it as a fully qualified name rooted at the DNS root.
- **`3600`** — the TTL (Time to Live) in seconds; here, one hour.
- **`IN`** — the class, almost always `IN` for internet.
- **`A`** — the record type.
- **`203.0.113.10`** — the IPv4 address the name resolves to.

Most hosting and registrar dashboards hide the zone-file syntax and just ask for a host (often `@` for the root domain or a subdomain label like `www`), a value (the IP address), and a TTL. Under the hood, they build the line above.

> Note: `203.0.113.10` is a documentation-only example address. Use the real public IP your host assigns — never a private range like `192.168.x.x`, which is unreachable from the public internet.

## Creating a DNS A record

![Six steps to create a DNS A record, from logging in to your DNS management interface to saving so the record propagates.](/images/figures/what-is-a-dns-a-record-understanding-the-fundamentals-fig1.webp)
*Exact menus vary by provider — check your DNS provider's documentation for specifics.*

The exact menus differ by provider, but the flow is consistent:

1. Log in to the DNS management interface at your registrar or DNS host.
2. Open the DNS or zone-editor section for the domain you want to change.
3. Add a new record and choose the **A** type.
4. Enter the host (`@` for the apex, or a label such as `www`) and the IPv4 address.
5. Set a TTL — a lower value if you expect to change the address soon.
6. Save. The record then propagates as resolvers refresh their caches.

You can confirm the result at any time with a [DNS lookup tool](/tools/dns-lookup), which queries the live record so you are not guessing from a cached browser result.

## A records, hosting, and load balancing

When you buy hosting, the provider assigns your server a public IP. Pointing your domain's A record at that IP is what connects the name to the machine. During a migration, you update the A record to the new server's IP and traffic follows once caches expire — which is exactly why you lower the TTL before a move.

A single hostname can also carry **multiple A records**, each with a different IP. Resolvers hand these back in rotation (round-robin), spreading requests across several servers for basic load distribution and redundancy. It is not a full load balancer — it does no health checking — but it is a simple way to share traffic.

## TTL and DNS A records

The **TTL** tells resolvers how long to cache the record before asking again. A short TTL (say 300 seconds) makes changes propagate quickly, which is ideal right before a migration or IP change. A long TTL (a day or more) cuts query volume and is fine for records that rarely change. The common pattern is to drop the TTL a day ahead of a planned change, make the change, confirm it, then raise the TTL again.

## Common issues with DNS A records

### My A record change hasn't taken effect yet

Resolvers serve the old value until the previous TTL expires, so a change can take anywhere from minutes to a full day depending on the TTL that was in place *before* you edited it. Verify the authoritative answer with a [DNS lookup](/tools/dns-lookup) rather than your browser, and [flush your local DNS cache](/learning/what-is-a-dns) if you still see the old address.

### The site loads on one network but not another

This usually means the record is inconsistent across your authoritative name servers, or a stale cache is serving an old IP in one location. Confirm every authoritative server returns the same value, and check whether an [AAAA record](/learning/what-is-an-aaaa-dns-record-quad-a-explained) is sending IPv6 clients to a different, misconfigured address.

### I pointed the A record at a private IP and nothing works

Addresses in `10.x`, `172.16–31.x`, and `192.168.x` are private and not routable on the public internet. A public site needs the public IP your host assigned. Swap the value for the correct public address.

### I need a CNAME and an A record on the same name

You can't. A hostname with a [CNAME record](/learning/what-is-a-cname-record) must not carry any other record of the same name, and the domain apex cannot be a CNAME at all — use an A record (or your provider's ALIAS/flattening feature) at the apex instead.

## Frequently asked questions

### Can one domain have both an A record and an AAAA record?

Yes, and most well-configured domains do. The A record answers IPv4 clients and the [AAAA record](/learning/what-is-an-aaaa-dns-record-quad-a-explained) answers IPv6 clients. Publishing both maximizes reachability, and clients automatically pick the protocol they can use.

### Does an A record affect my email?

Not directly — mail routing is governed by [MX records](/learning/what-is-an-mx-record), and authentication by [SPF](/learning/what-is-spf), [DKIM](/learning/what-is-dkim), and [DMARC](/learning/what-is-dmarc). But an A record can matter indirectly: some receivers check that the sending host has forward and reverse DNS that agree, which relies on a correct A record for the mail server.

### What's the difference between an A record and a CNAME?

An A record points a name straight at an IP address. A [CNAME](/learning/what-is-a-cname-record) points one name at *another name*, which is then resolved to an IP. Use an A record when you control or know the IP; use a CNAME to alias onto a hostname a provider manages for you.

### Why can't I put an A record and a CNAME on the same hostname?

DNS forbids a CNAME from coexisting with any other record type on the same name, because a CNAME says "this name is really that name" — which leaves no room for a separate address. At the domain apex you must use an A record (or an ALIAS/flattening feature) rather than a CNAME.

### How do I check my current A record?

Run a query with a [DNS lookup tool](/tools/dns-lookup) or `dig example.com A` from a terminal. Both read the live authoritative record, which is more reliable than trusting a browser that may have cached an older answer.

## Where Palisade fits

Palisade's job starts once the basics resolve: it checks your authentication records end to end and moves your domain toward enforcement. Run a free [Email Security Score](/tools/email-security-score) to see your SPF, DKIM, and DMARC status alongside the DNS records that support them.

## Related reading

- [What are DMARC, DKIM, and SPF?](/resources-post/what-are-dmarc-dkim-and-spf)
- [What is a CNAME record?](/learning/what-is-a-cname-record)
- [What is an AAAA DNS record (Quad-A explained)?](/learning/what-is-an-aaaa-dns-record-quad-a-explained)