CISCOTDP

CISCOTDP, or Cisco Technical Discovery Protocol, is a proprietary Cisco Systems protocol used to gather information about directly connected Cisco devices on a network. It operates at Layer 2 of the OSI model and is typically used on Ethernet or serial interfaces. The primary purpose of CISCOTDP is to discover and advertise information such as device type, operating system version, and configured hardware. This allows devices to identify their neighbors and exchange basic network intelligence.

CISCOTDP is often a prerequisite for other Cisco protocols to function correctly. For instance, it is essential for the operation of Cisco Discovery Protocol (CDP), which is a more widely known and utilized protocol for device discovery. While CDP is more feature-rich, CISCOTDP serves as a foundational element for certain Cisco device interactions. It is important to note that CISCOTDP is a legacy protocol and has largely been superseded by CDP in modern Cisco networks. However, understanding its existence and function can be helpful when troubleshooting older network equipment or specific Cisco configurations. The protocol operates by sending out periodic hello messages containing device information, and receiving similar messages from other connected Cisco devices.