CDP vs LLDP - Layer 2 Discovery Protocols
An overview and comparison of two Layer 2 discovery protocols, Link Layer Discovery Protocol (LLDP) and Cisco Discovery Protocol (CDP), which are both used to identify neighboring network devices. It explains that CDP is a Cisco proprietary protocol that is enabled by default and sends advertisements every 60 seconds, while LLDP is an industry standard protocol that is disabled by default and sends advertisements every 30 seconds. Both protocols utilize Type, Length, and Value (TLV) fields to communicate information like device identification and VLAN data, which is especially useful for carrying voice VLAN information to IP phones. The text includes various commands for globally enabling or disabling these protocols and for viewing neighbor and traffic information on network switches. Ultimately, the document serves as a reference for configuring and verifying these essential network discovery mechanisms.