Barash Helvadzhaoglu
Senior Network Security Engineer — Munich
11+ years designing and securing enterprise networks across banking, manufacturing, and critical infrastructure. I write about real-world architecture decisions, vendor tradeoffs, and lessons learned in the field.
Recent Posts
When a Catalyst 3560 Won't Boot: Recovery from the Boot Loader
Recovering a Cisco Catalyst 3560 stuck at the switch: prompt — boot loader variables, booting a different …
Cisco Catalyst 3560 Password Recovery: Two Methods, Step by Step
How to recover a lost enable or console password on a Cisco Catalyst 3560 — keep the configuration with the …
Cisco Catalyst 3560 IOS Upgrade: Two Methods and Verification
Upgrading IOS on a Cisco Catalyst 3560 — archive download-sw versus manual copy and boot system, flash space, …
What Is SD-WAN? A Practical Guide for Network Engineers
A comprehensive technical guide to SD-WAN: how it works, key components, traffic steering, and why enterprises …
802.11 Standards Deep Dive: WiFi 4, 5, 6, 6E and What Actually Changed
802.11 standards deep dive — what n, ac, ax, and be deliver in real deployments, OFDMA, MU-MIMO, BSS Coloring, …
WiFi Design for SMB, Hotels, and Medical Practices: Field Notes
WiFi design for SMBs, hotels, and medical practices — density planning, guest segmentation, PMS integration, …