Operation Diagnosis
198
9.8
Topology Discovery
Basic Configuration
Release
6.0
07/2010
9.8 Topology Discovery
9.8.1 Description of Topology Discovery
IEEE 802.1AB describes the Link Layer Discovery Protocol (LLDP). LLDP
enables the user to have automatic topology recognition for his LAN.
A device with active LLDP
X sends its own connection and management information to neighboring
devices of the shared LAN. This can be evaluated there once these
devices have also activated LLDP.
X receives connection and management information from neighboring
devices of the shared LAN, once these devices have also activated LLDP.
X sets up a management information schema and object definition for
saving information of neighboring devices with active LLDP.
A central element of the connection information is the exact, unique ID of a
connection point: MSAP (MAC Service Access Point). This is made up of a
device ID unique within the network and a port ID unique for this device.
Content of the connection and management information:
X Chassis ID (its MAC address)
X Port ID (its port MAC address)
X Description of the port
X System Name
X System description
X Supported system capabilities
X Currently activated system capabilities
X Interface ID of the management address
X Port VLAN ID of the port
X Status of the autonegotiation at the port
X Medium, half and full duplex settings and speed setting of the port
X Information about whether a redundancy protocol is switched on at the
port, and which one (for example, RSTP, HIPER-Ring, Fast-HIPER-Ring,
MRP, Ring Coupling).