Articles
In-depth articles on CIDR notation, subnetting, private IP ranges, AWS VPC design, cloud networking, and network engineering — published regularly as new topics come up.
Looking for quick reference material? The Guides section has concise how-to pages on specific topics. These articles go deeper — more context, more background, more real-world application.
Zero-Trust Networking: CIDR as an Explicit Trust Boundary
Zero-trust architecture rejects the idea that being inside a network perimeter makes traffic trustworthy. CIDR blocks become explicit policy statements about what can talk to what, not implicit trust zones.
Designing a Home Lab Network with Private IP Ranges
A well-designed home lab network avoids the conflicts that occur when your lab overlaps with your VPN or cloud infrastructure. Here's how to plan address space that stays out of your way.
The 100.64.0.0/10 Shared Address Space: CGNAT Explained
RFC 6598 reserves 100.64.0.0/10 for Carrier-Grade NAT — a mechanism ISPs use to share public IPs among thousands of customers. If you see 100.x.x.x addresses, this is why.
IP Address Management (IPAM): Tools and Best Practices
As networks grow, tracking which IP addresses and CIDR blocks are allocated, in use, or available becomes critical. IPAM tools — from spreadsheets to dedicated platforms — prevent conflicts and enable automation.
BGP and CIDR: How the Internet Exchanges Routing Information
BGP is the routing protocol that connects the internet's 80,000+ autonomous systems. CIDR is the addressing scheme that makes BGP routing tables manageable. Here's how they work together.
Firewall Hardening with CIDR: Moving Beyond 0.0.0.0/0
Allowing 0.0.0.0/0 in a firewall rule means "all of the internet." Replacing broad rules with specific CIDR blocks dramatically reduces your attack surface.
Monitoring Cloud IP Ranges: AWS and GCP Prefixes Change Without Warning
Cloud providers add and retire IP prefixes regularly. If your firewall rules or allowlists reference specific cloud CIDR blocks, you need a process to keep them current — or you will break production.
NAT Explained: How One Public IP Serves an Entire Office
Network Address Translation allows thousands of devices to share a single public IP address. Understanding how NAT works explains everything from home router behaviour to enterprise outbound firewalls.
The 127.0.0.0/8 Loopback Range: More Than Just localhost
Most engineers know 127.0.0.1 as localhost. But the entire 127.0.0.0/8 range — 16 million addresses — is reserved for loopback. Here's what that means and when the other addresses matter.
Subnetting for Beginners: From /24 to /28 in 10 Minutes
Subnetting divides a larger network into smaller, more manageable segments. This step-by-step tutorial walks through the maths using a /24 as the starting point.
How to Check If an IP Address Falls Within a CIDR Block
Determining whether a given IP address belongs to a specific CIDR range is a common task in security analysis, routing, and access control. Here are multiple approaches — manual math, tools, and code.
Azure IP Ranges and Service Tags: What Network Engineers Need to Know
Azure organises its IP ranges into Service Tags — named groups covering specific services and regions. Understanding how to use them simplifies firewall rules and is essential for hybrid connectivity.