Dell Force10 S4810P Configuration Manual page 642

Figure 30-1. Type, Length, Value (TLV) Segment
TLVs are encapsulated in a frame called an LLDP Data Unit (LLDPDU)
transmitted from one LLDP-enabled device to its LLDP-enabled neighbors. LLDP is a one-way protocol.
LLDP-enabled devices (LLDP agents) can transmit and/or receive advertisements, but they cannot solicit
and do not respond to advertisements.
There are five types of TLVs. All types are mandatory in the construction of an LLDPDU except Optional
TLVs. The inclusion of individual Optional TLVs is user configurable.
Table 30-1. Type, Length, Value (TLV) Types
Type TLV
0 End of LLDPDU
1 Chassis ID
2 Port ID
3 Time to Live
— Optional
642
| Link Layer Discovery Protocol (LLDP)
Description
Marks the end of an LLDPDU
An administratively assigned name that identifies the LLDP agent
An administratively assigned name that identifies a port through which TLVs are sent
and received
A value that tells the receiving agent how long the information contained in the TLV
Value field is valid
Includes sub-types of TLVs that advertise specific configuration information. These
sub-types are Management TLVs, IEEE 802.1, IEEE 802.3, and TIA-1057
Organizationally Specific TLVs.
(Figure 30-2), which is