Lldp Messages - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

LLDP runs over the Data Link Layer, so devices that use different Network
Layer protocols can still identify each other.
The ProCurve Secure Router automatically participates in LLDP so that the
router can learn about the devices to which it connects and so that it can
inform other devices of its presence.
Interfaces on the ProCurve Secure Router that run LLDP include:
Ethernet interfaces
Point-to-Point Protocol (PPP) interfaces
High-level Data Link Control (HDLC) interfaces
Frame Relay subinterfaces
demand interfaces

LLDP Messages

Figure 12-2 illustrates the format for an LLDP message.
Bytes
0 6
12 13
Slow protocol frame
Multicast Source
destination address
address
Figure 12-2. LLDP Message Sent over Ethernet
On Ethernet networks, LLDP messages are encapsulated in an 802 Slow
Protocol frame, which includes a multicast destination address and the source
MAC address of the transmitting interface. The Slow Protocol frame encap-
sulates the LLDP header and message.
Although LLDP is defined as an Ethernet protocol (802.1ab), any Layer 2
protocol can use it. ProCurve Secure Router WAN interfaces, as well as
Ethernet interfaces, run LLDP.
14 15 0 1 2 3 0
LLDP header Type
Time to
live
Link Layer Discovery Protocol
Overview
1 2 3 4 . . .
Length Value
(e.g. MAC address)
12-3