. While it was foundational for CCNA Discovery and Exploration curricula, it has been largely superseded by newer versions (currently v9.0.0) that support IoT and modern industrial security features.
Absolutely—for the right audience. If you typed into a search engine, you likely have a specific need: an older computer, a classic textbook, or a desire for a lean, no-nonsense simulator. Packet Tracer 5.1 delivers exactly that. a classic textbook
S. Alshammari, "Evaluating Packet Tracer as a Virtual Lab for Network Experiments" (conference paper) or a desire for a lean
Many older textbooks, lab manuals, and instructor guides were written specifically for the Packet Tracer 5.x series. Students following these materials will find that commands, menus, and device behaviors perfectly match version 5.1. a classic textbook