technology

OSPF stands for Open Shortest Path First. It is an open-standard link-state interior gateway protocol used by routers to learn network topology and calculate routes inside an autonomous system. This is the first Open-Source Networking Engineer Certification (OSNEC) lesson. The technician pathway teaches device addressing and verification; the engineer pathway now moves into routing behavior,…

A MAC address, short for Media Access Control address, identifies a network interface on a local network. You will commonly see it written as six pairs of hexadecimal characters, such as 3C:52:82:1A:4F:90. In OSNTC.001, you learned that an IP address identifies where a device communicates on an IP network. A MAC address serves a different…

A string is text stored in a program. In C++, std::string can hold words, player names, messages, and labels. Unlike the numbers we stored in OSC++.012, a string stores a sequence of characters. This is a new subject, not another vector lesson. 1. Make a String The #include <string> line makes the standard string type…

An interlock or permissive adds a condition to an electrical control circuit. Instead of allowing a device to run whenever START is pressed, the circuit checks whether another required condition is satisfied first. This lesson builds directly on OSETC.017. The simple technician idea is: a permissive says “this must be true before you may start,”…

A ladder diagram is a simple way to draw and understand an electrical control circuit. It gets its name because the drawing resembles a ladder: two vertical rails with horizontal lines, called rungs, between them. This lesson builds directly on OSETC.015 and OSETC.016. You already learned about relay and contactor coils, normally open and normally…

A motor starter is a control assembly used to start and stop an electric motor while providing important motor protection. A common magnetic starter combines a contactor with an overload relay. The contactor switches power to the motor; the overload relay helps protect the motor from damaging sustained overcurrent. This lesson builds directly on OSETC.015.…

Relays and contactors are electrically controlled switches. A small control signal energizes a coil, and the resulting magnetic field changes the position of one or more contacts. This lets a control circuit switch another electrical circuit without requiring a person to operate the contacts by hand. For a technician, the essential idea is simple: coil…

Single-phase and three-phase describe two common ways alternating-current (AC) electrical power is delivered. A technician does not need advanced power-system math to recognize the basic difference: single-phase power uses one repeating AC waveform, while three-phase power uses three AC waveforms separated by 120 electrical degrees. This lesson follows OSETC.012 on grounding and bonding and OSETC.013…

The Windows getmac command displays the MAC addresses associated with network adapters on a computer. A MAC address is a hardware-level identifier used by network interfaces, and technicians often need it when troubleshooting switches, DHCP reservations, device inventory, or adapter identity. Basic Syntax Running the command without options lists the physical addresses detected for local…

Learn how GFCIs detect current imbalance, where they appear, how TEST and RESET work, and what this essential shock-protection device cannot do.

The Linux whoami command tells you which user account the current command is running as. It is one of the simplest Linux commands, but it is useful when troubleshooting permissions, working over SSH, using sudo, or checking which account a script is using. Basic Syntax If your current effective user is student, the command prints:…

A Python package is a way to organize related modules together. Think of a package as a folder for Python code that belongs to the same part of a project. This lesson follows OSPython.008 on modules/imports, OSPython.009 on virtual environments, and OSPython.010: pip and Package Installation. Now we will build a tiny package of our…