Implementing Link Layer Discovery Protocol
Because CDP is a Cisco proprietary protocol, you cannot use it in networks with various vendors. In such a case, you must use the Link Layer Discovery Protocol (LLDP). It is an open standard protocol and, just like the CDP protocol, runs over the data link layer (Layer 2) to exchange information about network devices and their capabilities.
Because the LLDP is an open standard, it is supported by a wider range of network devices. LLDP has a lower overhead than CDP and can be used on lower-end devices with limited processing power. Moreover, it is more flexible and supported by many network devices, including switches, routers, and access points.
Note: LLDP is disabled by default on Cisco devices, but you can always enable it when required. However, using LLDP differs slightly from using CDP on Cisco devices. You cannot enable or disable it on any interface until the protocol is globally enabled.