Understanding IP Addresses
IPv4 and IPv6, public vs private (RFC 1918), static vs dynamic, CGNAT, and how addresses are assigned to your devices.
ShowMyIP Learning Center
Clear, accurate guides to the technology behind the tools you use here. Start with one of the three pillar guides below to build a solid foundation in IP addressing, DNS and network security, then dig deeper with our focused reference articles.
Start here: foundational guides
How DNS Works
Follow a lookup from your resolver to the root, TLD and authoritative servers — plus record types, TTL, caching and propagation.
Network Security Basics
TLS/SSL, ports and firewalls, VPNs and proxies, IP blacklists, device fingerprinting and password hygiene — the essentials, explained.
Reference articles & deep dives
What Is an IP Address?
A complete beginner-friendly introduction to IP addresses, how data is routed, and how to find your own IP.
How to Hide Your IP Address
VPN, Tor, proxies and public Wi-Fi compared honestly — and how to verify your real IP is actually hidden.
IPv4 vs IPv6 Explained
A side-by-side comparison of address space, notation, NAT and real-world adoption between the two IP versions.
DNS Record Types Explained
A, AAAA, CNAME, MX, TXT, NS, SOA and more — what each DNS record does and when you use it.
How to Check Email Deliverability
Diagnose why messages land in spam using SPF, DKIM and DMARC, and learn the checks that protect your sending reputation.
How to Fix DNS Server Not Responding
Step-by-step fixes for the "DNS server not responding" error and slow DNS lookups on Windows, Mac and your router.
How to Flush DNS Cache
Exact commands to clear the DNS cache on Windows, macOS and Linux, plus the browser cache, and how to verify it worked.
Best DNS Servers in 2026
Compare Cloudflare, Google, Quad9, OpenDNS and AdGuard on speed, privacy and filtering, and learn how to switch on any device.
What Is a MAC Address?
How MAC addresses work: the 48-bit format and OUI vendor prefix, MAC vs IP, and how to find yours on any device.
What Is a Static IP Address?
Static vs dynamic IPs explained: the pros and cons, who needs a static IP, how to get one, and how to check your IP type.
What Is a Subnet Mask?
Subnetting explained: dotted-decimal vs CIDR notation, network vs host bits, and how to work out the network, broadcast and usable hosts.
Subnet Cheat Sheet (CIDR /8 to /32)
A complete CIDR reference: subnet mask, wildcard mask, total addresses and usable hosts for every prefix, with worked examples.
What Is an SSL Certificate Chain?
Root, intermediate and leaf certificates explained: how the chain of trust validates, why "incomplete chain" errors happen, and how to fix them.
What Is a Port Number?
Ports and port forwarding explained: the well-known/registered/dynamic ranges, a common-ports table, TCP vs UDP, and whether port forwarding is safe.
JSON Syntax Explained
Objects vs arrays (curly braces vs square brackets), the six data types, valid vs invalid rules, why JSON has no comments, and common errors.
About these guides
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