Configuring LLDP
Overview
In a heterogeneous network, a standard configuration exchange platform makes sure different types of network devices from different vendors can discover one another and exchange configuration.
The Link Layer Discovery Protocol (LLDP) is specified in IEEE 802.1AB. The protocol operates on the data link layer to exchange device information between directly connected devices. With LLDP, a device sends local device information as TLV (type, length, and value) triplets in LLDP Data Units (LLDPDUs) to the directly connected devices. Local device information includes its system capabilities, management IP address, device ID, port ID, and so on. The device stores the device information in LLDPDUs from the LLDP neighbors in a standard MIB. LLDP enables a network management system to quickly detect and identify Layer 2 network topology changes.
For more information about MIBs, see "Configuring SNMP."
Basic concepts
LLDP frame formats
LLDP sends device information in LLDP frames. LLDP frames are encapsulated in Ethernet II or SNAP frames.
•LLDP frames encapsulated in Ethernet II
Figure 195 LLDP frame encapsulated in Ethernet II
Table 69 Fields in an Ethernet II encapsulated LLDP frame
Field | Description | |
Destination MAC address | MAC address to which the LLDP frame is advertised. It is fixed to | |
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Source MAC address | MAC address of the sending port. | |
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Type | Ethernet type for the upper layer protocol. It is 0x88CC for LLDP. | |
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| 217 |