DTP

Over the past week, I’ve been learning more about Dynamic Trunk Protocol. Dynamic Trunking Protocol is one of Cisco’s proprietary networking protocols, some of Cisco’s other proprietary protocols include VTP (VLAN Trunking Protocol), CDP (Cisco Discovery Protocol), and EIGRP (Enhanced Interior Gateway Routing Protocol). Dynamic Trunking Protocol focuses on negotiating trunking links between 2 or more VLAN (Virtual Local Area Network) aware switches. This protocol allows different switches to automatically update their switch port status accordingly and work with other devices smoothly. Dynamic Trunk Protocol works at Layer 2 in the OSI model. Dynamic Trunk Protocol may use the IEEE 802.1Q protocol or the Cisco ISL trunking protocols. There are 5 main port statuses that Dynamic Trunk Protocol works with: No-Negotiate, Dynamic Auto, Dynamic Desirable, Access, and Trunk. No-Negotiate is applied to ports that are interacting with non-Cisco devices as they don’t have the protocol and need to be manually configured. Dynamic Auto is a passive port status that is willing to be a Trunk port but will be an Access if the other end is also a Dynamic Auto or Access. Dynamic Desirable is the status the actively tries to enter as a Trunk port but will be an Access only if connected to another Access port. Access ports will be access ports unless connected to a Trunk port. Trunk ports take precedence over all other types. Overall the Dynamic Trunk Protocol allows for larger scale networks to dynamically change without constant manual configuration making the network more efficient and easier to manage.