Jeremy's IT lab
https://www.youtube.com/@JeremysITLab
Videos and flash cards + packet tracer labs
Les Réseaux de Guy Pujolle
Wi-Fi 7 / 8, 5G / 6G, réseaux quantiques, constellations de satellites...
La dernière édition 2024-2026 vient de paraître !
Pretty good explanations in the cisco meraki documentation: https://documentation.meraki.com/
eg. explanation for layer 2 and layer 3 switches and their differences
https://documentation.meraki.com/MS/Layer_3_Switching/Comparing_Layer_3_and_Layer_2_Switches