DNS

Like many of us, whenever I thought of DNS, my mind immediately went to public DNS like Google (8.8.8.8) — resolving domains like google.com.
But today I went deeper into concepts like:
🔹 Private DNS
🔹 DNS Zones
🔹 DNS Records
And the most interesting realization was around how DNS records get created for VMs in a cloud environment.
At first, I assumed that simply linking a Virtual Network (VNet) to a DNS Zone would automatically create DNS records.
👉 But that’s NOT the full story.
Here’s the key learning:
✔ A DNS Zone is like a database of domain records
✔ A VNet link allows resources to resolve those records
✔ But automatic DNS record creation depends on auto-registration
So when auto-registration is enabled:
➡️ A VM created in that VNet automatically gets a DNS record (name → private IP)
If it’s not enabled:
➡️ You’ll need to create DNS records manually
💡 Analogy that helped me:
DNS Zone = Phonebook
VNet Link = Access to the phonebook
Auto-registration = Auto-saving contacts
This small distinction cleared up a big confusion for me.
If you're learning cloud networking (especially Azure), this is something worth understanding early — it saves a lot of head-scratching later 😄