Networking & DNS tutorials

Networking and DNS explained simply: record types, subdomains, propagation, reverse DNS, Cloudflare, CDN, IPv6, private networks and email records.

Email DNS records: SPF, DKIM and DMARC

Set up SPF, DKIM and DMARC so your emails reach the inbox, not spam.

IPv6 is the future of internet addresses. Here is how to enable and check it on your server.

Pick a single version of your domain, with or without www, and redirect the other for SEO and consistency.

A CDN delivers content close to visitors, faster. Here is how it works and when it is worth it.

Link your servers through an encrypted WireGuard tunnel, so they communicate securely without exposing services to the internet.

Reverse DNS links an IP back to a name and is essential for email delivery. Here is how it works.

Cloudflare offers fast DNS, global cache and basic protection for free. Here is how to connect it to your server.

After you change a DNS record, it takes time to update everywhere. Here is why, and how to check the status.

ping, traceroute, dig, curl and ss: the basic tools for diagnosing network problems.

Use subdomains like app.example.com or blog.example.com for separate services, on the same server or others.

A, AAAA, CNAME, MX, TXT, NS: what each DNS record means and when to use it.