Junior Network Administrator case studies
Junior Network Administrator · Put your knowledge to work in context.
The Junior Network Administrator credential is an entry-level certification for people who are moving into hands-on network operations: help-desk technicians stepping up, career changers who have completed a foundational course, and students preparing for their first infrastructure role. It signals that a candidate can reason about how packets move, how addresses are planned, and how a small network is built, secured, and kept running. The Junior Network Administrator case studies are 5 cases and about 3,151 words.
1VLSM for a Branch Build-Out with a Borrowed WAN Range
A regional office has been assigned the block 172.20.16.0/22. The branch router connects to two access/distribution switches and to the HQ WAN edge, so three point-to-point links are needed, each a /30.
661 words, about 3 min2IP Phones and Guest Wi-Fi on a Misconfigured Trunk
A dental clinic has one 48-port access switch serving VLAN 10 (clinical workstations), VLAN 20 (IP phones), VLAN 30 (patient guest Wi-Fi) and VLAN 99 (management, 10.99.0.0/24). Desks have an IP phone with the PC daisy-chained behind it.
619 words, about 3 min3Warehouse WLAN: Co-Channel Interference and a PoE Budget Question
A 120 m × 60 m distribution warehouse with 12 m steel racking is covered by 12 ceiling-mounted access points. Handheld barcode scanners are 2.4 GHz-only 802.11n devices; the APs are dual-band but no client uses 5 GHz.
631 words, about 3 min4Morning APIPA Outage at a 300-Seat Call Centre
A 300-seat call centre runs one flat data VLAN, 10.10.10.0/24, with DHCP and DNS on a Windows server at 10.10.10.5 in the same VLAN, lease duration 8 days. Desk hard phones sit in VLAN 20 (10.10.20.0/24) and are served by the same DHCP server via ip helper-address on the VLAN 20 SVI; phones are stable.
599 words, about 3 min5Classroom Loop, Rogue DHCP and a Flat VLAN 1
A K-12 school has a single 48-port closet switch. Every access port is switchport mode access in VLAN 1, port security is not enabled, trunks between switches run native VLAN 1, and DTP is left at its default.
641 words, about 3 min