The Data Link Layer is one of my favorite layers of the OSI Model. Like a father who loves ALL of his children equally, but in different ways, I also love the other layers, but Layer 2 will always ...

Networking author Howard C. Berkowitz provides tips on avoiding and fixing data link network failures in Part 3 of his series.

Sometimes long runs use CWDM/DWDM which is more of a layer 1 but some implementations bleed into l2 in my opinion as they encapsulate other protocols (like ethernet).