HP 5820X Series

202
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 these categories: basic management TLVs, organizationally (IEEE 802.1 and IEEE
802.3) specific TLVs, and LLDP-MED (media endpoint discovery) TLVs. Basic management TLVs are
essential to device management. Organizationally specific TLVs and LLDP-MED TLVs are used for
enhanced device management; they are defined by standardization or other organizations and are
optional to LLDPDUs.
1. Basic management TLVs
Table 23 l
ists the basic management TLV types currently in use. Some of them must be included in every
LLDPDU.
Table 25 Basic LLDP TLVs
Type Description Remarks
Chassis ID Bridge MAC address of the sending device
Port ID
ID of the sending port
If the LLDPDU carries LLDP-MED TLVs, the port ID TLV carries the
MAC address of the sending port or the bridge MAC in case the
port does not have a MAC address. If the LLDPDU carries no
LLDP-MED TLVs, the port ID TLV carries the port name.
Time To Live Life of the transmitted information on the receiving device
End of LLDPDU Marks the end of the TLV sequence in the LLDPDU
Mandatory
Port Description Port description of the sending port
System Name Assigned name of the sending device
System Description Description of the sending device
System Capabilities
Identifies the primary functions of the sending device and the
enabled primary functions
Management Address
Management address, and the interface number and OID
(object identifier) associated with the address
Optional
2. IEEE 802.1 organizationally specific TLVs
Table 26 IEEE 802.1 organizationally specific TLVs
Type Description
Port VLAN ID Port’s VLAN identifier. 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
Textual name of any VLAN to which the port belongs. An LLDPDU can carry
multiple different TLVs of this type.
Protocol Identity
Indicates protocols supported on the port. An LLDPDU can carry multiple
different TLVs of this type.
DCBX Data center bridging exchange protocol