Information Technology Fundamentals and Infrastructure
What to Know
Expect coverage of hardware, operating systems, networking, and service delivery models. Know the OSI and TCP/IP layers and which device or protocol operates at each (switch at layer 2, router at layer 3, DNS and HTTP at application layer). Understand IP addressing basics, subnetting purpose, DHCP, NAT, and the difference between LAN, WAN, VPN, and the internet. Distinguish IaaS, PaaS, and SaaS by what the provider manages versus what the customer manages. Know virtualization, containers, hypervisors, and the cloud characteristics (on-demand self-service, elasticity, measured service). Storage types (SAN, NAS, DAS), backup versus redundancy, availability concepts (uptime, failover, load balancing), and disaster recovery metrics RTO and RPO. Also know client-server versus peer-to-peer and the role of middleware and APIs.
Traps
Questions blur backup and redundancy: redundancy keeps service running, backup restores data after loss. RTO is recovery time; RPO is tolerable data loss measured in time. SaaS questions often test that the customer still owns identity, access, and data governance. Layer questions misplace protocols - for example, claiming TCP operates at the network layer. Another trap treats virtualization as identical to containers; containers share the host kernel while virtual machines each run a full OS.
Worked Example
A firm needs a system that survives a data center outage with at most 15 minutes of lost transactions and two hours to restore service. Rule of thumb: read "lost data" as RPO (15 minutes) and "time to restore" as RTO (two hours). Then choose mechanisms - synchronous replication or frequent log shipping for RPO, warm standby or automated failover for RTO - and verify cost against criticality.
Exam Tip
Map each requirement sentence to one metric or service model before evaluating answer choices.