January 31, 2020 update: No, you're not crazy. Cisco changed the exam number from 300-401 to 350-401. For your convenience, I've put together the following list of my courses that cover the new CCNP ENCOR exam. By watching and following along with the hands-on demos in these courses, you can't go wrong. Routing …

Following are free resources that I've created or collected. Articles by me Networking Web-scale: a healthy choice for healthcare networks Automating Cumulus Linux with Ansible 5 Network automation tips and tricks for NetOps Top 5 tips for transitioning to 100G networking 5 big misconceptions about virtual LANs IT …

AWS Certified Solutions Architect Study Guide: Associate SAA-C02 Exam 3nd Edition AWS Certified Solutions Study Guide: Associate (SAA-C02) Exam, Third Edition comprehensively and efficiently prepares you for the SAA-C02 Exam. The study guide contains robust and effective study tools that will help you succeed on the …

You took one of the Cisco CCNP exams. You went to the exam center, sat down, and started the exam. About 2 hours later, you saw the dreaded news appear on the screen: You didn’t pass. I’ve failed certification exams in the past, so I can relate to the facepalm-worthy feeling you get when you realize you dropped a …

I recently got an email from a viewer of my Practical Networking course who asked how the TCP/IP networking terms I used mapped to the Open Systems Interconnect (OSI) model. First, a bit of background. The OSI model is a generic networking model that is supposed to describe conceptually how networks carry data. Within …

Puzzled by networking on AWS? Check out my AWS networking deep dive series! AWS Networking Deep Dive: Route 53 DNS Configure Route 53 for any domain name, and configure health checks and routing policies.  AWS Networking Deep Dive: Virtual Private Cloud (VPC) Create secure and scalable VPCs. Implement multi-VPC …

You probably know the popular Google DNS server IP addresses by heart: 8.8.8.8 and 8.8.4.4. Before those were around you might have even used Level3’s 4.2.2.1 and 4.2.2.2. Of course, everyone else uses these too, which means these popular servers are under a pretty heavy load. Fortunately, there are faster public DNS …