Supported Advertisements (TLVs)
LLDP defines a set of common advertisement messages. These are distributed in Type Length Value (TLV) format in an LLDP packet (see LLDP Packets).
The individual advertisements within the packet are called TLVs, and each TLV advertises device information or a device capability. Certain TLVs are mandatory and are always advertised after LLDP is enabled; optional TLVs are advertised only when so enabled by default or during configuration.
The following sections provide more information on TLVs.