INTRODUCTION
LLDP, Link Layer Discovery Protocol, enables Ethernet network devices, such as switches and routers, to transmit and/or receive device-related information to or from directly connected devices on the network, and to store such information learned about other devices. The data sent and received by LLDP is useful for many reasons.
- The switch can discover neighbors—other devices directly connected to it.
- Devices can use LLDP to advertise some parts of their Layer 2 configuration to their neighbors
- The LLDP-MED extension provides a level of plug & play configuration of peripheral devices.(ie. POE & IP Phone Voice VLAN)
LLDP is a link level (“one hop”) protocol; LLDP information can only be sent to and received from devices that are directly connected to each other, or connected via a hub or repeater. LLDP packets are not forwarded on to other devices on the network.
LLDP operates over physical ports (Layer 2) only. For example, it can be configured on switch ports that belong to static or dynamic aggregated links (channel groups), but not on the aggregated links themselves; and on switch ports that belong to VLANs, but not on the VLANs themselves.
LLDP Implementation
To enable LLDP on switches running AlliedWare Plus software execute the following commands:
awplus# configure terminal
awplus(config)# lldp run
By default, transmission and reception of LLDP advertisements is enabled on all ports. To disable the transmission and/or reception of LLDP advertisements on one or more interfaces execute the following commands:
awplus(config)# interface {port-list}
awplus(config-if)# no lldp {[transmit][receive]}
LLDP commands to review current LLDP configurations within the AlliedWare Plus:
awplus#show lldp
awplus#show lldp interface [<port-list>]
awplus#show lldp local-info [base] [dot1] [dot3] [med] [interface <port-list>]
awplus#show running-config lldp
LLDP commands to used to monitor LLDP operations and display neighbor information as needed.
awplus#show lldp neighbors
awplus#show lldp neighbors detail
awplus#show lldp statistics
awplus#show lldp statistics interface [<portlist>]
For more advanced LLDP configuration such as LLDP-MED extensions for media endpoint device management , please refer to the Software Reference Guide for your switch running AlliedWare Plus.