Configuring for Network Management Applications

LLDP (Link-Layer Discovery Protocol)

Configuration Options

Enable or Disable LLDP on the Switch. In the default configuration, LLDP is globally enabled on the switch. To prevent transmission or receipt of LLDP traffic, you can disable LLDP operation (page 13-38)

Enable or Disable LLDP-MED.In the default configuration for the switches covered in this guide, LLDP-MED is enabled by default. (Requires that LLDP is also enabled.) For more information, refer to “LLDP-MED (Media- Endpoint-Discovery)” on page 13-53.

Change the Frequency of LLDP Packet Transmission to Neighbor

Devices. On a global basis, you can increase or decrease the frequency of outbound LLDP advertisements (page 13-38).

Change the Time-To-Live for LLDP Packets Sent to Neighbors. On a global basis, you can increase or decrease the time that the information in an LLDP packet outbound from the switch will be maintained in a neighbor LLDP device (page 13-38).

Transmit and Receive Mode. With LLDP enabled, the switch periodically transmits an LLDP advertisement (packet) out each active port enabled for outbound LLDP transmissions, and receives LLDP advertisements on each active port enabled to receive LLDP traffic (page 13-49). Per-Port configuration options include four modes:

■Transmit and Receive (tx_rx): This is the default setting on all ports. It enables a given port to both transmit and receive LLDP packets, and to store the data from received (inbound) LLDP packets in the switch’s MIB.

■Transmit only (txonly): This setting enables a port to transmit LLDP packets that can be read by LLDP neighbors. However, the port drops inbound LLDP packets from LLDP neighbors without reading them. This prevents the switch from learning about LLDP neighbors on that port.

■Receive only (rxonly): This setting enables a port to receive and read LLDP packets from LLDP neighbors, and to store the packet data in the switch’s MIB. However, the port does not transmit outbound LLDP packets. This prevents LLDP neighbors from learning about the switch through that port.

■Disable (disable): This setting disables LLDP packet transmissions and reception on a port. In this state, the switch does not use the port for either learning about LLDP neighbors or informing LLDP neighbors of its pres­ ence.

13-38