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 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, and authentication by SPF, DKIM, and 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 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 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.

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What is a DNS A Record: Understanding the Fundamentals

By Samuel ChenardAugust 9, 2023Updated July 20, 20267 min read

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In brief

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.

What is a DNS A Record: Understanding the Fundamentals

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, 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 that carry SPF and DKIM, and the MX records 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, 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:

Technical exampletext

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.

Exact menus vary by provider — check your DNS provider's documentation for specifics.

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

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

You can confirm the result at any time with a DNS lookup tool, 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 rather than your browser, and flush your local DNS cache 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 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 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.

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 to see your SPF, DKIM, and DMARC status alongside the DNS records that support them.

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