A vs CNAME: choose the record your provider expects

What does this mean?

An A record supplies an IPv4 address. A CNAME supplies another DNS name as an alias. They are not interchangeable text fields: entering a hostname in an A record or an IP address in a CNAME field is not a correct substitute for the provider’s instructions.

What should I check first?

Check whether the hosting service supplies an IP address or a destination hostname. Note the name being configured, especially whether it is www or the root domain. The target of a CNAME is a DNS name, without https://, a path or a trailing page name.

How can I diagnose the cause?

Query existing A, AAAA and CNAME records for the exact name. Compare both IPv4 and IPv6 with the intended host. A correct A record can coexist with a stale AAAA record and still leave some visitors reaching an old server. Avoid changing nameservers when only one address record needs correction.

How do I fix it safely?

For www, use the provider’s specified record type and destination. At the root domain, an ordinary CNAME conflicts with required zone data; some providers offer ALIAS, ANAME or flattening instead. Follow that provider’s documented apex method rather than forcing a CNAME into a panel that rejects it.

Verify the fix and know when to contact your provider

Copy the old records before saving. Retest resolution and then HTTP behavior because DNS alone does not configure redirects or certificate coverage. Ask the host for the exact root and www setup if its alias instructions are unclear. Preserve MX and email TXT records while fixing a web address.

Work through these checks in order

1. If the host supplied 192.0.2.10 as an illustrative address, its format belongs in an A field; if it supplied a service hostname, that belongs in the documented alias field. Never use an illustrative address as a real production destination.
2. Check whether the target is the root domain or www. Ask the DNS provider about its supported apex-alias feature if the host supplies a hostname for the root.
3. After saving the confirmed real value, query that exact name and test HTTPS. A DNS alias does not configure the application hostname, certificate or canonical redirect for you.

Which tool can help?

DNS lookup · DNS record explainer

DNS tools show one resolver’s public answers. Record explainers do not authenticate a message, and calculators do not monitor a server. Use the evidence alongside your provider’s logs.