DNS records
A record set is one (name, type) tuple inside a zone, holding one or more values. www.example.com → A → 203.0.113.5 is a single-value A record set; multi-value sets (round-robin DNS) hold N values under one set id.
Supported record types
| Type | Purpose | Example value |
|---|---|---|
| A | IPv4 address | 203.0.113.5 |
| AAAA | IPv6 address | 2001:db8::1 |
| CNAME | Alias to another name | other.example.com. |
| MX | Mail exchanger | 10 mail.example.com. |
| TXT | Free text — verification, SPF, DKIM, DMARC | "v=spf1 -all" |
| SRV | Service location | 10 5 5060 sip.example.com. |
| NS | Delegation to other nameservers | ns1.other.com. |
| CAA | Cert-authority authorization | 0 issue "letsencrypt.org" |
| PTR | Reverse-DNS pointer (for floating IPs) | See floating IPs |
We don't support: ALIAS / ANAME (CNAME-flattening at the apex) — use the CNAME at a subdomain instead, or an A record pointing at a floating IP at the apex.
Multi-value records
You can put multiple values in one record set:
www.example.com → A → 203.0.113.5
→ 203.0.113.6
→ 203.0.113.7The nameservers serve all three values per query, and resolvers spread requests across them — basic round-robin load balancing without an LB. For real load balancing you'd point the record at a load balancer VIP instead; multi-value is for cases where the client + resolver can handle failover on their own (most modern HTTP clients can).
TTLs
Each record set has a TTL in seconds — how long resolvers cache the answer before re-querying. Defaults:
- A / AAAA / CNAME: 300 seconds (5 minutes) — friendly for rapid updates / failover
- MX / NS: 3600 (1 hour) — these change rarely
- TXT for verification: 60 — short to make verification re-checks fast
Pick lower TTLs while you're actively iterating; bump them up once the records stabilize, to reduce query volume + cost.
What's next
- DNS zones — the container records live in.
- Floating IPs — common A/AAAA target.
- Load balancers — VIP target for higher-traffic services.