DNS records explained: A, CNAME, MX, TXT and NS

The records you will meet

• A record: points a name to an IPv4 address. This is how yourbusiness.in finds your website's server. AAAA is the same for IPv6.
• CNAME record: makes one name an alias of another name. "www" is often an alias of the main name.
• MX record: says which servers receive email for the domain. Each has a priority; the lowest number is tried first.
• TXT record: holds text that other systems read, such as SPF, DKIM, DMARC and "prove you own this domain" codes.
• NS record: says which name servers hold the domain's records. Change these and you change where all the other records are managed.

TTL: why changes are not instant

Every record has a time to live, in seconds or minutes, which tells resolvers how long they may remember the answer. After a change, some places still show the old answer until their copy expires. This is called propagation. Lowering the TTL a day before a planned change shortens the wait.

Before you edit

• Note down what is there now. A wrong edit to an MX record can stop your email.
• Change one thing at a time, then check it.
• If a service gives you a record to add, copy it exactly, including any dots and underscores.

Check a change

The free DNS propagation checker shows what several public resolvers return for a name and record type right now. Check the record you changed; if it still shows the old value, wait for the old TTL to run out and look again.