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

Link Layer Discovery Protocol

Viewing LLDP Information

12-4
The ProCurve Secure Router supports a network control protocol (NCP)
called the LLDP Control Protocol (LLDPCP). This protocol allows PPP peers
to negotiate the exchange of LLDP messages encapsulated in PPP frames.
The router can also exchange LLDP messages over a Frame Relay or an ATM
PVC. A Frame Relay frame can use Sub-Network Access Protocol (SNAP) to
identify encapsulated Ethernet protocols such as LLDP. ATM subinterfaces
that use AAL5 Link Layer Control/ Sub-Network Access Protocol (LLC/SNAP)
encapsulation similarly exchange LLDP messages. If the ATM subinterface
uses AAL5 MUX encapsulation for PPP frames, then the LLDP messages can
be exchanged as described for a PPP connection.
The LLDP header includes, in addition to the version field and flags, a time to
live (TTL) field. The TTL informs devices how long they should store the
information included in the message.
The actual information in the message consists of a type length value (TLV)
field. Each TLV communicates information about the interface. The informa-
tion includes:
chassis ID—MAC address
port ID—the interface ID (such as ppp 1)
network address at which a management process can find the device
system name—the device's hostname
system description—for example, the router's model and current Secure
Router OS software
system capabilities—the device type (such as router or bridge)
You can prevent interfaces on the ProCurve Secure Router from sending some
or all of these messages.
Viewing LLDP Information
The ProCurve Secure Router automatically runs LLDP with settings suitable
for a typical network. Before you alter these settings, you should examine the
information that the router is actually sending and receiving.
You should also understand how LLDP works so that you can capitalize on
the information LLDP interfaces collect.