“DNS is the lifeblood of the internet.”
If you’ve worked in networking long enough, you’ve heard the phrase:
“It has to be DNS.”
Right up there with “It’s always MTU.”
And more often than not… it really is DNS.
This article exists for one reason: As an Internet Service Provider, you should be running your own DNS infrastructure. DNS is not optional. It is a core dependency of your service, just like routing, switching, and transport. If you don’t control it, you don’t truly control your network.
Why Running Your Own DNS Matters
DNS directly impacts:
If all your customers use 8.8.8.8 or 1.1.1.1, you have:
Ask yourself this:
If Google or Cloudflare DNS has an outage… what leverage do you have?
The answer is simple: None.
Hardware Options: From Budget to Enterprise
Your DNS hardware doesn’t need to be fancy—it just needs to be reliable.
Under 500 Users
Two Raspberry Pi systems running Pi-hole
Or two used small-form-factor PCs from eBay
Example: HP EliteDesk 800 (i5, 8GB RAM, 256GB SSD) for under $100
Intel NUCs work great too
Anything is better than nothing—just make it redundant.
Enterprise Deployment
What we commonly deploy:
With six 800GB SAS drives, you’re looking at roughly $3,200 per server, but these platforms:
They are absolutely overpowered for just DNS—which is why we typically run Proxmox or Hyper-V and host additional services as well.
The Core Software Stack: Pi-hole + Unbound
What matters most is how you run DNS—not just the hardware.
Pi-hole
Acts as the front-end caching DNS server
Default cache: 10,000 entries
We tune ours to 250,000 cached entries
Network-wide telemetry, ad, malware, and phishing blocking
Full visibility into DNS behavior
Unbound
High-performance recursive DNS resolver
Talks directly to root servers
Eliminates reliance on Google, Cloudflare, or upstream forwarders
Provides secure, authoritative recursion
How We Use Them Together
This gives you:
✅ Full recursion
✅ Full caching
✅ Full visibility
✅ Full control
✅ No dependency on public DNS vendors
Security Without Becoming “The ISP That Blocks Everything”
As an ISP, you typically don’t want aggressive filtering. But malware and phishing domains should never be accessible.
We implement:
1–2 strictly malware & command-and-control focused blocklists
About 500,000 malicious DNS entries
No ad blocking by default
No content filtering
This protects customers from:
Even if a device becomes compromised, blocking DNS-based command and control often prevents the malware from functioning at all.
Real Performance Gains
On production networks, we consistently see:
On a 32-core 3.2GHz Xeon DNS VM, usage is typically:
DNS is lightweight. Performance is not the challenge. Architecture is.
Alternative: Windows-Based Recursive DNS
For Windows-based environments:
SimpleDNS
It’s a solid option for Windows-heavy infrastructures.
Placement Matters: Keep DNS at the Network Edge
DNS should live:
✅ Inside your network
✅ Close to customers
✅ On low-latency infrastructure
It should not live in AWS, Azure, or third-party cloud platforms unless you are specifically engineering global anycast DNS.
Lower latency = faster lookups = faster perceived internet speed.
The Business Reality
Here’s the real question every ISP must answer:
If your customers’ DNS is broken… can you directly fix it?
If you rely on:
Then the answer is no.
And if you have:
No control
No monitoring
No logs
No escalation path
Then you are outsourcing one of the most critical components of your network—for free—to companies that owe you nothing.
That’s not engineering.
That’s gambling.
Final Thought
DNS is not an optional service.
It is not an add-on.
It is not a nice-to-have.
DNS is a core requirement of the internet.
If you are an Internet Service Provider, then:
✅ You should control your recursive DNS
✅ You should own your cache
✅ You should protect your customers from malware
✅ You should have visibility during outages
✅ You should not bet your reputation on a free public service
Run your own DNS.
Your customers, your engineers, and your uptime will thank you.
