Link Layer Discovery Protocol (Lldp); Lldp Overview - ZyXEL Communications XMG1930 Series User Manual

Link Layer Discovery Protocol

32.1 LLDP Overview

The LLDP (Link Layer Discovery Protocol) is a layer 2 protocol. It allows a network device to advertise its
identity and capabilities on the local network. It also allows the device to maintain and store information
from adjacent devices which are directly connected to the network device. This helps an administrator
discover network changes and perform necessary network reconfiguration and management. The
device information is encapsulated in the LLDPDUs (LLDP data units) in the form of TLV (Type, Length,
Value). Device information carried in the received LLDPDUs is stored in the standard MIB.
The Switch supports these basic management TLVs.
• End of LLDPDU (mandatory)
• Chassis ID (mandatory)
• Port ID (mandatory)
• Time to Live (mandatory)
• Port Description (optional)
• System Name (optional)
• System Description (optional)
• System Capabilities (optional)
• Management Address (optional)
The Switch also supports the IEEE 802.1 and IEEE 802.3 organizationally-specific TLVs.
IEEE 802.1 specific TLVs:
• Port VLAN ID TLV (optional)
• Port and Protocol VLAN ID TLV (optional)
IEEE 802.3 specific TLVs:
• MAC/PHY Configuration/Status TLV (optional)
• Link Aggregation TLV (optional)
• Maximum Frame Size TLV (optional)
The optional TLVs are inserted between the Time To Live TLV and the End of LLDPDU TLV.
Chapter 32 Link Layer Discovery Protocol (LLDP)
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