Dell PowerConnect 5548 User Guide - Page 532

LLDP Overview The Link Layer Discovery Protocol (LLDP) enables network managers to troubleshoot and enhance network management by discovering and maintaining network topologies over multi-vendor environments. LLDP discovers network neighbors by standardizing methods for network devices to advertise themselves to other systems, and to store discovered information. Discovery information includes: • Device identification • Device capabilities • Device configuration The advertising device transmits multiple advertisement message sets in a single LAN packet. The multiple advertisement message sets are sent in the packet's Type Length Value (TLV) field. LLDP devices must support chassis and port ID advertisements, as well as system name, system ID, system description, and system capability advertisements. LLDP Media Endpoint Discovery (LLDP-MED) increases network flexibility by enabling various IP systems to co-exist on a single network, and provides the following features: • Detailed network topology information, including information on which devices are located on the network and where the devices are located, for example, which IP phone is connect to which port, which software is running on which switch, and which port is connected to which device. • Automatic deployment of policies over networks for: - QoS Policies - Voice VLANs • Emergency Call Service (E-911) via IP phone location information. • Troubleshooting information. LLDP MED sends network managers alerts for: - Port speed and duplex mode conflicts - QoS policy misconfigurations 532 Dell PowerConnect 55xx Systems User Guide