Demystifying VLAN Trunk Protocol

Of the many protocols that Cisco has created over the years, one of the most feared and often misunderstood is VTP, or Virtual Local Area Network (VLAN) Trunk Protocol. The original intention was simple: create a straightforward, scalable method for VLAN administration across multiple switches in a network. Due to the way that the technology works, however, significant problems can arise unintentionally and cause widespread outages in an existing network. The purpose of this white paper is to examine the inner workings of VTP in detail and create strategies for safe use in production environments.