Network Layers Courses
University of Michigan via Coursera Demystifying Networking
NPTEL via Swayam Introduction to Networking
New York University (NYU) via edX PyTorch
YouTube CompTIA Network+ Course Certification
Cybrary Troubleshooting Network Connectivity
LinkedIn Learning Introduction to Networking Basics with CCNA
Packt via FutureLearn CS402: Computer Communications and Networks
Saylor Academy Networks - Cristina Formaini and Peter Faiman
White Hat Cal Poly via YouTube Digital Investigation: Ethernet, IP, TCP and UDP Protocols
Bill Buchanan OBE via YouTube