DNS Troubleshooting: What to Do When Sites Don't Load

It's 9am. Your receptionist can't access the scheduling software. Two employees can't log into the payroll portal. Your shipping software shows "site not found."

Your internet is working—you can ping Google. But specific sites won't load.

This is almost always DNS.

What DNS actually does

DNS (Domain Name System) translates names like "payroll.company.com" into IP addresses like "192.168.1.100." Your computer doesn't actually understand names—it needs numbers. DNS is the translator.

When DNS breaks, your computer can't find where to send requests. The site exists, your internet works, but nothing resolves.

The symptoms

You have a DNS problem if:

• One specific site won't load but others do
• Your VPN connects but can't access internal resources
• Email works but web-based tools don't
• Some apps work and others don't (each app might use different DNS servers)

Quick fixes (try these first)

1. Flush your DNS cache

Your computer remembers recent DNS lookups. Sometimes this cache gets corrupted.

On Windows:

ipconfig /flushdns

On Mac:

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

2. Try a different DNS server

Your router or ISP's DNS might be the problem. Change your DNS to Google (8.8.8.8 and 8.8.4.4) or Cloudflare (1.1.1.1).

On Windows:

1. Settings > Network & Internet > Adapter options
2. Right-click your connection > Properties
3. Select Internet Protocol Version 4 > Properties
4. Select "Use the following DNS server addresses"
5. Enter 8.8.8.8 and 8.8.4.4
6. Click OK

On Mac:

1. System Preferences > Network > Advanced > DNS
2. Remove existing entries
3. Add 8.8.8.8 and 8.8.4.4
4. Click OK > Apply

3. Restart your router

Routers have DNS settings too. A 30-second power cycle clears router-level DNS cache.

4. Try incognito/private browsing mode

Browser extensions can sometimes cause DNS-level issues. Private mode uses system DNS settings directly.

5. Check if the site itself is down

Go to downdetector.com or use a status page check. If the site is having widespread issues, your DNS isn't the problem.

What can go wrong

ISP DNS outage. Your internet provider's DNS servers go down. This happens more than you'd think.

Router DNS issues. Cheap routers sometimes have DNS bugs or limitations. The router caches lookups and serves stale or incorrect data.

Domain expiration. The domain owner's registration lapsed. DNS stops working entirely. This happens when credit cards expire or payments fail.

DNS provider outage. If the domain uses a specific DNS provider that goes down, the site disappears from the internet entirely.

Propagation delays. After changing DNS records, changes take time to spread across the internet—anywhere from 5 minutes to 48 hours. During this window, different people might see different results.

Malware or hijacking. Some malware redirects your DNS to malicious servers. If flushing DNS doesn't help, run a malware scan.

Internal DNS problems. If you're trying to access internal resources (file servers, internal apps), the problem might be your internal DNS server, not the internet.

How to check if DNS is the problem

Use nslookup (command line tool)

Open Command Prompt (Windows) or Terminal (Mac) and type:

nslookup sitename.com

If it returns "server can't find" or times out, DNS is your problem.

Use ping

ping sitename.com

If ping returns an IP address but the site won't load in your browser, the issue is somewhere else (likely browser-related).

Use dig (more advanced)

On Mac or Linux, dig gives you detailed DNS lookup information:

dig sitename.com

This shows which DNS server answered, the response time, and the actual records returned.

What it costs when DNS breaks

For a business with 5 employees and average hourly revenue:

• 30 minutes of downtime: $200-$500 in lost productivity
• A full morning of DNS issues: $1,000-$3,000

Multiply by your actual numbers. For most Gulf Coast small businesses, DNS problems cost real money in wasted time and frustrated staff.

Vendor questions (copy/paste)

For your IT support:

• "How is DNS configured at our location? Who manages it?"
• "What DNS servers do we use? Are they redundant?"
• "What happens to our DNS if our primary internet goes down?"

For your domain registrar:

• "Who manages DNS for our domains? What's the login in case of emergency?"
• "Are our domains set to auto-renew? What's the current expiration date?"

For a new DNS provider:

• "What's your uptime guarantee? How do you handle DNS propagation?"
• "Do you offer DNSSEC (DNS Security Extensions)?"
• "What's your support process if a DNS attack happens?"

Minimum viable implementation

Basic DNS hygiene:

1. Know who manages your DNS. This should be documented.
2. Have login access to your domain registrar and DNS provider.
3. Set calendar reminders for domain renewals 30 days before expiration.
4. Use your ISP's DNS only as a backup. Primary DNS should be Google (8.8.8.8) or Cloudflare (1.1.1.1).

If you manage your own DNS:

1. Use at least two DNS providers for redundancy (primary and secondary).
2. Set low TTL (Time To Live) values before making changes. High TTLs mean slow propagation.
3. Document your DNS records. Spreadsheets go stale—use a configuration management tool or at least a maintained text file.

When to hire help

• DNS problems keep recurring and you can't identify the root cause.
• You're locked out of your domain registrar and need emergency access.
• A domain expired and you need help recovering it (possible but not guaranteed).
• You've been hit with DNS hijacking (your DNS records changed without your knowledge—this is a security emergency).
• You need help setting up redundant DNS for critical internal applications.

DNS is invisible until it breaks. A few minutes of documentation now prevents hours of troubleshooting later.