Why do network administrators need to understand binary, and what number systems are commonly used in networking?

Question

Accepted Answer

Hosts, servers, and routers identify each other using binary addressing, so understanding it is needed to read and troubleshoot addresses. The three systems are binary (base 2), decimal (base 10), and hexadecimal (base 16).
Hosts, servers, and routers use binary addressing - understanding binary helps administrators identify and troubleshoot network issues.
Three number systems used in networking:

Number System
Base
Digits Used
Common Use

Binary
2
0, 1
How devices process data

Decimal
10
0-9
Human-readable IPv4

Hexadecimal
16
0-9, A-F
IPv6 and MAC addresses

Go deeper:

Why Use Binary? — Computerphile — the physical reason digital devices count in two states rather than ten.
 Wikipedia — Binary number — base-2 fundamentals that underpin every address a device handles.

Number System	Base	Digits Used	Common Use
Binary	2	0, 1	How devices process data
Decimal	10	0-9	Human-readable IPv4
Hexadecimal	16	0-9, A-F	IPv6 and MAC addresses