NCoE Selection Test study guide
NCoE Selection Test · Work through your exam, one topic at a time.
The NCoE Selection Test is a skills-based screening exam used to identify engineers ready to work in a Network Center of Excellence environment. It is aimed at network professionals who already hold foundational certification-level knowledge and now need to demonstrate operational judgement: reading a topology, choosing a path, hardening access, and diagnosing faults under time pressure. The NCoE Selection Test study guide has 7 sections and about 2,559 words.
01Network Fundamentals and Protocols
The exam treats the layered model as a diagnostic index, not a memory drill. Map the PDUs in order: data → segment (TCP/UDP) → packet (IP) → frame (Ethernet) → bits.
365 words, about 2 min02Routing and Switching
An 802.1Q trunk inserts a 4-byte tag, reducing usable MTU to 1496 and reserving a VLAN ID field of 12 bits (1–4094 usable). The native VLAN is sent untagged on 802.1Q links; a mismatch does not bring the trunk down, it silently merges two broadcast domains and leaks traffic across VLANs.
374 words, about 2 min03Network Security and Access Control
AAA separates authentication, authorisation and accounting. TACACS+ uses TCP 49 and encrypts the entire payload, making it the usual choice for device administration.
381 words, about 2 min04Network Services and Infrastructure (DNS, DHCP, Load Balancing, WAN)
Authoritative servers hold zone data; resolvers recurse. Common records: A and AAAA for addresses, CNAME as an alias (never at a zone apex), MX for mail with preference values, NS for delegation, SOA for serial and negative-caching timers, TXT for SPF/DKIM/verification, SRV for service location, and PTR for reverse lookup.
378 words, about 2 min05Monitoring, Troubleshooting, and Performance Analysis
SNMP polling gives counters and interface state; v3 adds authentication and privacy, so v2c community strings should be treated as legacy. Traps are unsolicited UDP notifications and can be lost - do not treat silence as health.
337 words, about 2 min06Automation, Scripting, and Configuration Management
NETCONF runs over SSH on port 830 and uses YANG-modelled XML; RESTCONF exposes YANG data over HTTP(S) with JSON or XML; gNMI suits streaming telemetry. Model-driven interfaces return structured data, which is why they beat screen-scraping CLI output with regular expressions.
354 words, about 2 min07Documentation, Change Management, and Operational Best Practices
A usable package includes logical and physical topology diagrams, an IP address management record (subnets, VLANs, VRFs, allocations), interface and patch-panel port maps, rack elevations, a device inventory with serial numbers, EoL/EOS dates and contract IDs, circuit records with provider references, and runbooks for routine tasks. Diagrams decay fastest - attach them to a change record so updates are mandatory, not optional.
370 words, about 2 min