The DNS records a server needs
Which record does what, who sets it, and the order that saves you a day of debugging.
Pointing a name at your machine
- A — name to IPv4 address. The basic one.
- AAAA — name to IPv6 address. Add it once the service actually listens on IPv6; see getting IPv6 running.
- CNAME — an alias to another name. Never on the bare domain, and never alongside other records on the same name.
These live with whoever runs your DNS. Not with us, unless you asked us to host the zone.
The one we set
PTR, the reverse record, belongs to whoever holds the IP address — so for our addresses, us. Mail us the mapping and we set it; see IP addresses and reverse DNS. Make sure the forward record exists first and points back at the same address, otherwise it is worse than having no PTR at all.
If the machine sends mail
In this order, because each builds on the previous:
- PTR on the sending address, matching a name that resolves back.
- SPF — a TXT record listing who may send for your domain.
One record, not three, and end it with
-allonce you are sure. - DKIM — your mail server signs, the public key sits in DNS.
- DMARC — start at
p=nonewith a reporting address, read the reports for a few weeks, then tighten.
Skip these and large receivers will quietly bin your mail. See sending mail from your server.
Two habits worth having
Lower the TTL to five minutes a day before you plan to change anything — it turns a cutover from hours into minutes. And after any change, check what the world actually sees rather than what your own resolver cached.
Still stuck? Mail support@novogara.com — an engineer answers, at any hour. Back to the knowledge base