CPDN case studies
CPDN · Put your knowledge to work in context.
CPDN is a professional certification for practitioners who design, deploy, operate and defend IT infrastructure and the services running on it. It is aimed at administrators, engineers and consultants who already work hands-on with systems and networks and want an external validation of both conceptual knowledge and operational judgement, and at candidates moving from a specialist or support role into a broader engineering position. The CPDN case studies are 5 cases and about 3,426 words.
1The 200 Mbit/s WAN That Feels Like Dial-Up
A logistics firm centralised its ERP client in a Dallas data centre serving six depots, including Singapore and Perth. Last quarter it upgraded every WAN circuit from 20 Mbit/s to 200 Mbit/s MPLS at an extra USD 18,000 per month.
679 words, about 3 min2Designing the Refresh With Three Engineers and No Room for a Rework
A manufacturer is refreshing two data centres with USD 900,000 total capital. Each holds 240 VMs on a three-tier estate.
664 words, about 3 min3Wired 802.1X Across a Hospital With Unpatchable Pumps
A 980-bed hospital has 42 IDFs and 11,000 access ports and is under an audit finding requiring authenticated wired access. A discovery scan found 6,200 endpoints in the CMDB and 1,900 MAC addresses that are not - infusion pumps, nurse-call handsets, HVAC controllers, label printers and vendor laptops.
667 words, about 3 min4The Audit Finding That Started as a Network Diagram
A 320-store retail chain runs a flat Layer 2 network in each store, extended to the data centre over an L2VPN. PIN pads encrypt card data, but it is decrypted on a Windows store server that also hosts CCTV recording, the guest Wi-Fi controller and the pharmacy label printer.
696 words, about 3 min5Four Hours of Silence
At 02:14 the ERP cluster failed over to the standby data centre after a leaf switch pair in the primary site flapped 40 times in 25 minutes. About 200 VMs saw up to 12% packet loss while ECMP and OSPF reconverged repeatedly.
720 words, about 4 min