IP Geolocation & DNS Lookup: Domain to Server Guide

How IP Geolocation Works

IP geolocation is not GPS — it relies on IP address allocation databases, and its accuracy depends on database quality.

Accuracy Level	Scope	Data Source
Country	Country	WHOIS allocation records
City	City/region	ISP reports + backbone routing
District	10-50km	Commercial databases (MaxMind)
Street	1-5km	WiFi/cellular positioning assist

IP geolocation cannot pinpoint an exact address — only an approximate area.

Look Up IP Information with ToolsKu

DNS Lookup

Open the DNS Lookup tool
Enter a domain (e.g., example.com)
Select a record type (A/AAAA/CNAME/MX/TXT/NS)
Click query and review the results

Whois Lookup

Open the Whois Lookup tool
Enter a domain
Review the registration information (registrar, creation date, expiration date, registrant)

DNS Record Types Explained

Type	Name	Purpose	Example
A	Address record	Domain → IPv4	`example.com → 93.184.216.34`
AAAA	IPv6 address	Domain → IPv6	`example.com → 2606:2800:220:1:...`
CNAME	Canonical name	Domain → another domain	`www.example.com → example.com`
MX	Mail exchange	Mail server	`example.com → mail.example.com (priority 10)`
TXT	Text record	SPF/DKIM/verification	`"v=spf1 include:_spf.google.com"`
NS	Name server	Domain name servers	`example.com → ns1.example.com`
SOA	Start of authority	Zone management info	Primary NS + admin email + serial
SRV	Service record	Service discovery	`_http._tcp.example.com → target:port`
CAA	Certificate authority	Restrict certificate issuance	`0 issue "letsencrypt.org"`

Common DNS Lookup Scenarios

Find a Website's IP

# Command line
dig example.com A
nslookup example.com

# Result
example.com.    3600    IN    A    93.184.216.34

Find Mail Servers

dig example.com MX

# Result
example.com.    3600    IN    MX    10 mail.example.com.
example.com.    3600    IN    MX    20 mail2.example.com.

Check SPF Records (Anti-Spam)

dig example.com TXT

# Result
example.com.    3600    IN    TXT    "v=spf1 include:_spf.google.com ~all"

The DNS Resolution Process

User enters example.com
  ↓
1. Browser DNS cache → hit? return
  ↓
2. OS DNS cache → hit? return
  ↓
3. Router DNS cache → hit? return
  ↓
4. ISP recursive resolver → hit? return
  ↓
5. Root name server (.) → returns .com NS
  ↓
6. .com TLD server → returns example.com NS
  ↓
7. example.com authoritative server → returns the A record
  ↓
Result: 93.184.216.34

DNS Cache Duration (TTL)

dig example.com

# ANSWER SECTION:
example.com.    3600    IN    A    93.184.216.34
#               ↑ TTL (seconds) = 1 hour

TTL Value	Use Case
300 (5 minutes)	Frequently changing (CDN, blue-green deployments)
3600 (1 hour)	Typical websites
86400 (1 day)	Stable services (email, NS)

Reading Whois Information

Key Fields in a Query Result

Domain Name: EXAMPLE.COM
Registrar: Google Domains LLC
Registrar URL: https://domains.google
Creation Date: 1995-08-14
Expiration Date: 2028-08-13
Name Server: NS1.GOOGLE.COM
Name Server: NS2.GOOGLE.COM
Registrant Organization: Example Inc.
DNSSEC: unsigned

Field	Meaning	Use
Registrar	Registrar	Where the domain is managed
Creation Date	Registration date	Judge the domain's age
Expiration Date	Expiration date	Prevent domain expiry
Name Server	DNS servers	Where DNS resolution is managed
Registrant	Registrant	Ownership info (may be privacy-protected)
DNSSEC	DNS security extensions	DNS response validation

Privacy Protection

# Without privacy protection
Registrant Name: John Doe
Registrant Email: john@example.com

# With privacy protection enabled
Registrant Name: REDACTED FOR PRIVACY
Registrant Email: Please contact registrar

Hands-On Network Troubleshooting

Scenario 1: Website Won't Load

1. DNS lookup → does the domain resolve?
   ❌ Doesn't resolve → DNS misconfiguration or expired domain
   ✅ Resolves → continue

2. Ping the IP → is the server reachable?
   ❌ Timeout → server down or firewall
   ✅ Reachable → continue

3. curl -I → what HTTP status code?
   301/302 → redirect issue
   403 → permission issue
   500 → server-side error
   200 → probably a front-end issue

Scenario 2: Email Delivery Fails

1. Check MX records → is the mail server configured correctly?
2. Check SPF records → is the sending server whitelisted in SPF?
3. Check DKIM records → is the signature correct?
4. Check DMARC records → is the email policy correct?

# Look up all email-related records at once
dig example.com MX
dig example.com TXT  # SPF + DKIM + DMARC all live in TXT records

Scenario 3: Verify a CDN Configuration

1. Check CNAME → does the domain point to a CDN?
   www.example.com → cdn.example.com.cdn77.org

2. Check A records → CDN edge node IPs
3. DNS lookups from multiple regions → verify CDN routes to the nearest node

Querying DNS with JavaScript

In the Browser (DoH)

// DNS over HTTPS (Cloudflare)
async function dnsLookup(domain, type = 'A') {
  const url = `https://cloudflare-dns.com/dns-query?name=${domain}&type=${type}`;
  const response = await fetch(url, {
    headers: { 'Accept': 'application/dns-json' },
  });
  const data = await response.json();
  return data.Answer;
}

// Usage
const records = await dnsLookup('example.com', 'A');
// [{ name: "example.com", type: 1, TTL: 3600, data: "93.184.216.34" }]

In Node.js

import { resolve } from 'node:dns/promises';

// Query A records
const addresses = await resolve('example.com', 'A');
// ["93.184.216.34"]

// Query MX records
const mxRecords = await resolve('example.com', 'MX');
// [{ exchange: "mail.example.com", priority: 10 }]

// Query all records
const anyRecords = await resolve('example.com', 'ANY');

FAQ

How Long Do DNS Changes Take to Propagate?

It depends on the TTL. If the old TTL was 3600 seconds, the worst case is 1 hour. Lower the TTL to 300 seconds before making DNS changes, wait for the old TTL to expire, then make the change.

Why Do DNS Results Differ by Location?

CDNs and Anycast return different IPs based on the user's location. This is expected behavior, not a DNS problem.

What Is DNSSEC For?

DNSSEC uses digital signatures to verify the authenticity of DNS responses, preventing DNS hijacking attacks. If DNSSEC validation fails, the browser refuses to connect.

Summary

IP geolocation and DNS lookup are fundamental network troubleshooting skills. Master DNS record types, the resolution process, and Whois interpretation, and you can pinpoint website issues quickly. ToolsKu offers two online tools — DNS Lookup and Whois Lookup — so you can troubleshoot networks right in your browser without installing command-line tools.