Layer 2 devices: Switches are bridges with more than 2 ports. Each port is it’s own collision
domain, fixing some of the issues with collisions. Uses MAC addresses to direct traffic. Good switch
security includes: Shutting unused ports down. Put ports in specific VLANs. Using the MAC Sticky
command to only allow that MAC to use the port, either with a warning or shut command if another MAC
accesses the port. Use VLAN pruning for Trunk ports.