Networks and the Internet
This domain tests how devices communicate, how the internet resolves names and moves packets, and how network security works. Expect questions on protocols, addressing, bandwidth versus latency, and basic troubleshooting.
Addressing and protocols
An IP address identifies a device interface on a network; a MAC address identifies a network interface at the link layer. DNS translates domain names into IP addresses. DHCP assigns addresses automatically. Data is broken into packets, routed across networks, and reassembled. TCP provides reliable, ordered delivery; UDP is connectionless and lower overhead. HTTP and HTTPS are application protocols; HTTPS uses TLS encryption. Routers connect networks; switches connect devices within a LAN.
Security
Firewalls filter traffic. Encryption protects confidentiality in transit. VPNs create encrypted tunnels but do not make a device trustworthy. Authentication, updates, and phishing awareness matter more than Wi-Fi hiding alone.
Worked example
A user can reach other websites, but one site fails by name. Pinging the site’s IP address succeeds, while pinging its domain name fails. That points to DNS resolution rather than total loss of connectivity. Checking DNS settings, flushing the DNS cache, or trying another resolver is a reasonable next step. If the IP ping also failed, the problem would be broader connectivity or the destination host.
Traps
The HTTPS padlock means the connection is encrypted, not that the content is true. IP and MAC addresses are not interchangeable. Bandwidth is capacity; latency is delay. Public Wi-Fi is not automatically safe just because a password is required.