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Tlvs – H3C Technologies H3C WX5500E Series Access Controllers User Manual

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TLVs

TLVs are type, length, and value sequences that carry information elements. The type field identifies the

type of information, the length field measures the length of the information field in octets, and the value
field contains the information itself.
LLDPDU TLVs fall into the following categories:

Basic management TLVs.

Organizationally (IEEE 802.1 and IEEE 802.3) specific TLVs.

LLDP-MED (media endpoint discovery) TLVs.

Basic management TLVs are essential to device management. Organizationally specific TLVs and

LLDP-MED TLVs are used for improved device management. They are defined by standardization or other

organizations and are optional to LLDPDUs.

1.

Basic management TLVs

Table 22

lists the basic management TLV types. Some of them are mandatory to LLDPDUs, that is,

must be included in every LLDPDU.

Table 22 Basic management TLVs

Type Description

Remarks

Chassis ID

Specifies the bridge MAC address of the sending device.

Mandatory.

Port ID

Specifies the ID of the sending port.
If the LLDPDU carries LLDP-MED TLVs, the port ID TLV carries the

MAC address of the sending port. Otherwise, the port ID TLV
carries the port name.

Time to Live

Specifies the life of the transmitted information on the receiving
device.

End of LLDPDU

Marks the end of the TLV sequence in the LLDPDU.

Port Description

Specifies the port description of the sending port.

Optional.

System Name

Specifies the assigned name of the sending device.

System
Description

Specifies the description of the sending device.

System
Capabilities

Identifies the primary functions of the sending device and the
enabled primary functions.

Management
Address

Specifies the management address, and the interface number and
OID associated with the address.

2.

IEEE 802.1 organizationally specific TLVs

Table 23 IEEE 802.1 organizationally specific TLVs

Type Description

Port VLAN ID

Specifies the PVID. An LLDPDU carries only one TLV of this type.

Port And Protocol VLAN
ID

Indicates whether the device supports protocol VLANs and, if so, what VLAN
IDs these protocols will be associated with. An LLDPDU can carry multiple

different TLVs of this type.

VLAN Name

Specifies the name of any VLAN to which the port belongs. An LLDPDU can
carry multiple different TLVs of this type.