CNAME record lookup

What the CNAME record lookup shows

A CNAME record lookup shows the alias published for a name: the canonical name queries for it are redirected to. The query goes to Cloudflare's 1.1.1.1 from the IPVIEW server over the toolkit's own DNS engine. The lookup asks for the CNAME record only, so it shows the alias published at that name and does not resolve the target; to see what the target resolves to, look up its A record, and the Full report follows the whole chain.

A CNAME must stand alone: the standard forbids any other record at the same name, which is why a domain apex, which needs NS and SOA records, cannot be one, and why providers invent flattening schemes for it. A CNAME at the apex, or an MX pointing at a CNAME, are faults some resolvers tolerate and others do not.

How to read the result

The table lists Name, Value and TTL; the value is the target. Anything the resolver returned beside the alias appears under Along the way; for a plain CNAME question that is usually nothing. A chain of aliases is allowed but costs a lookup per hop; the Full report walks it for up to ten hops, reports the final target and warns of a loop. The TTL here is the time left on 1.1.1.1's cached copy and can be lower than the TTL set in the zone; when the name is an alias, the Full report asks the zone's own nameservers for the CNAME's TTL.

The warning that matters is the dangling CNAME: an alias whose final target no longer has any address. The name still answers in DNS, but the target, often a decommissioned CDN or hosting endpoint, can be claimed by someone else and with it your subdomain. The Full report flags this only when the target definitely answered no address, not when it timed out. An empty answer here reads: No CNAME record, the name has its own records; The name does not exist at all, NXDOMAIN; The query failed, nothing follows.

When it is useful

A CDN, a hosted shop or a static-site host asked you to point a subdomain at their name and the site does not come up: see whether the alias is published, whether it points at exactly the name they gave you, and what the target resolves to. An SSL certificate check on the same name shows whether the provider has issued for it yet.

When cleaning up a zone, every CNAME pointing at a service the organisation no longer uses is a candidate for takeover; run the Full report, which lists the chain and flags a dangling target, and remove what is dead.

Common questions

What is a CNAME record?

An alias: it says one name is another name, so every query for the alias is answered from the target. www.example.com pointing at example.com, or shop.example.com at a provider's hostname, are the typical uses.

Can the root of my domain be a CNAME?

Not by the standard, because the apex must carry NS and SOA records and a CNAME may not share a name with anything. Providers offer ALIAS or ANAME records, or flattening, which publish A records instead.

What is a dangling CNAME?

An alias whose target no longer has an address, usually because the service behind it was shut down. If the target can be claimed by someone else, they control your subdomain. Remove aliases to services you no longer use.