JNCIA-Design case studies
JNCIA-Design · Put your knowledge to work in context.
JNCIA-Design is the associate-level design credential in the Juniper certification family, aimed at network engineers, pre-sales and solution architects, and operations staff who want to show they can plan networks rather than only configure devices. Candidates typically already hold a routing or switching associate certification or have hands-on experience with Junos, and are moving toward design-oriented or architecture roles. The JNCIA-Design case studies are 5 cases and about 4,174 words.
1Summarizable Address Plan for a Four-Site Distributor
NovaFreight is a regional distributor with four sites: headquarters (380 endpoints today), a northern depot (140), a southern depot (90), and a small DR suite (60). Everything sits inside a single 10.20.0.0/16 block carried by one OSPF area, and the recently acquired southern depot still uses 192.168.50.0/24 for its label printers because nobody has renumbered them.
799 words, about 4 min2PoE Budget and Cross-Floor Roaming in an Office Retrofit
An insurance firm is retrofitting three floors of a 1990s office block: 640 assigned seats, about 1,100 devices at the Monday 10:00 peak, and 72 Wi-Fi 6E access points (24 per floor) that draw 25.5 W each when the 6 GHz radio and 802.3bt are active. Each IDF holds six 48-port access switches with a 740 W PoE budget, fed by a single 30 A 208 V UPS circuit; a seventh switch is planned for growth.
845 words, about 4 min3Dual-Transport WAN for Fourteen Rural Clinics
Northstar Health runs 14 rural clinics served from a Dallas hub, with a Denver secondary hub for DR. Each clinic has a 20 Mbps MPLS circuit (99.95% SLA, 45 ms to Dallas) and a 200/50 Mbps business broadband line.
859 words, about 4 min4Two-Spine Data Centre Refresh Under an Optics Budget
Meridian Payments is refreshing a 36-rack data centre that will hold 288 dual-attached servers (8 per rack, 2 × 25 GbE each), an all-flash array with 8 × 100 GbE ports, and 80% east-west traffic between application tiers. The brief caps the spine layer at exactly two switches because of rack space and optics budget, targets 3:1 oversubscription at the leaf, and requires that a single spine failure still leaves at least 2:1.
825 words, about 4 min5OT/IT Segmentation for a Plant With Unpatchable HMIs
Calderon Foods operates one plant with 300 OT devices (PLCs, HMIs, and 12 Windows XP HMIs that cannot be patched until the line is rebuilt in 2027), 500 IT users, a DMZ with three public web servers, 200 guest devices, and vendor remote access for nine integrators. Everything is one flat 10.0.0.0/16 behind an internet-edge firewall; the only internal control is a router ACL between office and plant.
846 words, about 4 min