Point a domain name to your Linux VPS with DNS records

A domain name only becomes useful once its DNS records tell the world where your server lives. In this guide you will connect a domain to your VPS Linux Infrawire, add IPv4, IPv6 and www records, and check that everything resolves correctly.

📋 Prerequisites

• A VPS with a public IPv4 address (and optionally IPv6). From your client area you can find the IP and the root password of the VPS.
• A registered domain name (example.com) and access to its DNS zone, at your registrar or at a DNS provider.
• dig and nslookup on your workstation or on the VPS:

Bash
1# Ubuntu 24.04 / Debian 12
2sudo apt update && sudo apt install -y dnsutils
3
4# AlmaLinux 9 / Rocky 9
5sudo dnf install -y bind-utils

🧭 Understand the record types

A CNAME cannot live on the bare domain (example.com, the apex) because it would conflict with the other records of the zone. Use A/AAAA there, and a CNAME for subdomains such as www.

✍️ Create the A and AAAA records

In the DNS zone editor of your registrar, add these records. The host field @ stands for the bare domain.

TEXT
Type   Host   Value        TTL
A      @      VPS_IP       3600
AAAA   @      VPS_IPV6     3600

Some interfaces want the full name (example.com.) instead of @. Keep the trailing dot only if the editor asks for a fully qualified name. If you do not use IPv6 yet, skip the AAAA record: a wrong AAAA is worse than none, because many clients try IPv6 first.

🔗 Add www with a CNAME

Make www follow the main name so you only change the IP in one place:

TEXT
Type    Host   Value          TTL
CNAME   www    example.com.   3600

Other subdomains work the same way. Use an A record when a subdomain must point to a different server (api to another IP, for instance).

⏱️ TTL and propagation

The TTL (time to live, in seconds) tells resolvers how long they may keep an answer in cache. A new record usually appears within minutes, but a change to an existing record stays invisible until the old TTL expires.

• Before a migration, lower the TTL to 300 a day ahead, then change the IP.
• After the change is stable, raise it back to 3600 or more.
• Full propagation is never instant: expect from a few minutes to a few hours.

✅ Verify with dig and nslookup

Ask your own resolver, then ask a public one to compare:

Bash
1dig +short example.com A
2dig +short example.com AAAA
3dig +short www.example.com CNAME
4
5# Query a specific public resolver
6dig @1.1.1.1 +short example.com A
7dig @8.8.8.8 +short example.com A
8
9# Ask the authoritative servers directly (no cache)
10dig +short NS example.com
11dig @NAMESERVER +short example.com A

The same check with nslookup:

Bash
1nslookup example.com
2nslookup -type=AAAA example.com
3nslookup www.example.com 1.1.1.1

The answer must equal VPS_IP. Then test the path to the server:

Bash
1ping -c 3 example.com
2curl -I http://example.com

🔁 Reverse DNS (PTR)

Forward DNS turns a name into an IP. Reverse DNS (PTR record) does the opposite: it maps VPS_IP back to a hostname. It is not managed in your domain zone but by whoever owns the IP block, so ask your provider to set it. Mail servers rely on it heavily, so set it to the name you use to send mail, for example mail.example.com, and make sure that name has a matching A record.

Bash
1dig -x VPS_IP +short
2host VPS_IP

☁️ Special case: Cloudflare proxy

When a record is proxied (orange cloud), public DNS returns Cloudflare addresses, not VPS_IP. That is expected: dig will never show your server IP.

• Web traffic (80/443) goes through Cloudflare; other services such as SSH, mail or game servers do not.
• For anything that is not HTTP(S), create a record set to DNS only (grey cloud), for example ssh.example.com pointing to VPS_IP.
• Mail records (mail, MX targets) must always be DNS only.
• Keep SSL mode on Full (strict) and install a valid certificate on the VPS, otherwise you get redirect loops or error 525.

🛠️ Troubleshooting

The old IP still shows up. The previous TTL has not expired. Query the authoritative server with dig @NAMESERVER to confirm the zone is right, then wait. Flush your local cache if needed:

Bash
1sudo resolvectl flush-caches

NXDOMAIN or no answer. The record sits in the wrong zone, the host name has a typo, or the domain uses other name servers than the ones you edited. Compare dig NS example.com with the name servers declared at your registrar.

The domain resolves but the site does not load. DNS is fine; the problem is the service. Check that a web server listens on the port and that the firewall allows it:

Bash
1sudo ss -tlnp | grep -E ':80|:443'

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🎉 Your domain now points to your VPS: from here you can install a web server and issue a certificate.