DCNSA Level II
Network Security glossary
Every term this guide defines, A to Z, each with the chapter that teaches it. Open it when a word in a question is unfamiliar, and test yourself on it in the last week: cover the definition and say it in one sentence.
13 terms from the free first chapter
A
- Access control
Restricting who and what can connect to or use network resources, the first gate any user or device must pass.
Taught in Foundations of network security
- Antivirus
Software detecting and removing malicious code before, or after, it runs on a system.
Taught in Foundations of network security
- Application security
Hardening the applications running on the network against exploitation: secure coding practice, patching, and configuration that closes off unnecessary features an attacker could abuse.
Taught in Foundations of network security
- Attack
A deliberate attempt to exploit a vulnerability and compromise a system, distinguishing a genuine incident from a vulnerability that exists but has not (yet) been exploited.
Taught in Foundations of network security
B
- Behavioural analytics
Detecting anomalies by learning what normal network activity looks like for a given user or system, and flagging deviations that a signature-based tool would miss entirely, since the deviation itself, not a known malicious pattern, is what is detected.
Taught in Foundations of network security
D
- Data loss prevention (DLP)
Controls that detect and block sensitive data from leaving the network improperly, such as a large customer database being copied to an external drive or emailed outside the organisation.
Taught in Foundations of network security
F
- Firewall
Monitors and controls traffic entering and leaving the network based on defined rules, the network's first line of defence at its boundary.
Taught in Foundations of network security
M
- Malware
Malicious software, viruses, worms, ransomware and spyware, designed to damage, disrupt or steal from a system, and the target antivirus and behavioural analytics exist to catch.
Taught in Foundations of network security
N
- Network segmentation
Dividing a network into smaller isolated zones, so a breach in one segment does not automatically expose the whole network, developed fully in the chapter on deploying security solutions.
Taught in Foundations of network security
S
- Security
Protecting systems, networks and data from unauthorised access, damage or disruption, through a combination of technical controls, policy and trained behaviour.
Taught in Foundations of network security
- Social engineering attacks
Manipulating people, rather than exploiting a technical flaw, into revealing credentials or granting access: phishing, pretexting and impersonation, developed fully in the chapter on testing network vulnerability. No firewall or antivirus stops a user who is convinced to hand over their own password voluntarily.
Taught in Foundations of network security
V
- Vulnerability
A weakness in a system, in its software, configuration, or the people operating it, that a threat could exploit if left unaddressed.
Taught in Foundations of network security
W
- Web security
Controls protecting users and systems from web-based threats: malicious sites, drive-by downloads, and content filtering against known-bad destinations.
Taught in Foundations of network security
The full glossary adds every term from the other 4 chapters, A to Z, each with the chapter that teaches it.