Look closer.

Architecture: Private NAT and Overlapping IP Ranges in AWS

Two teams, two projects, two VPCs. Neither team talked to the other about addressing, so both grabbed the obvious default: 10.0.0.0/16 . Everything worked fine in isolation. Then a business requirement lands: an application in VPC A needs to call a service in VPC B . You reach for VPC peering, and AWS rejects it. You reach for a Transit Gateway, attach both VPCs, and watch one of your routes silently vanish from the route table. The problem is not … Read More

Explained: BYOIP (Bring Your Own IP)

You already own your IP addresses. Here's why that matters in the cloud. You run a company with servers in three places: your own data center, a colocated facility, and now AWS. Your servers have used the same block of public IP addresses for years. Clients, partners, firewall allowlists, and DNS records all point at those IPs. Then you launch an EC2 instance and AWS hands you a fresh IP from its own pool. Fine for most workloads. But what if … Read More

Explained: CIDR

You spin up a VPC in AWS and it asks for a CIDR block. You type 10.0.0.0/16 because that's what the tutorial said. Then you create a subnet and it wants another one, so you put 10.0.1.0/24 . It works. You move on. Six months later somebody asks why the subnet can only hold 251 usable addresses when you asked for 256, and whether 10.0.1.0/24 overlaps with the 10.0.0.0/22 block the networking team just allocated. You don't know. Nobody does.… Read More

Explained: AWS Global Accelerator

The failover drill was supposed to take five minutes. At 2:00 a.m. the team failed the primary region on schedule, the Route 53 health check noticed within seconds, and the DNS answer flipped to the standby site exactly as designed. Twenty minutes later, the dashboards told a different story. Nearly half the clients were still connecting to the dead region. Nothing was misconfigured; every layer was doing exactly what it was built to do. The reco… Read More