LLDP neighbor information not displayed in vCenter

Products

• VMware vSphere ESXi

Issue/Introduction

• A packet capture shows that the LLDP packets are reaching the ESXi host vmnic:

  pktcap-uw --uplink vmnic1 --dir 0 --ethtype 0x88cc -c 2 -o - | tcpdump-uw -ner -
  The name of the uplink is vmnic1.
  The session filter Ethernet type is 0x88cc.
  To capture 2 packets.
  <timestamp> ##:##:##:##:##:## > 01:80:c2:00:00:0e, ethertype LLDP (0x88cc), length 441: LLDP, length 427: 
  <timestamp> ##:##:##:##:##:## > 01:80:c2:00:00:0e, ethertype LLDP (0x88cc), length 441: LLDP, length 427:

• The LLDP tab for an ESXi host physical adapter shows no data:
  
  
  
• Command net-dvs -l in the ESXi host shows the switch is configured for com.vmware.etherswitch.cdp = CDP

Cause

This issue occurs because the Distributed Virtual Switch is configured to use CDP instead of LLDP. The VDS will only process and display discovery information for the protocol currently selected in its properties.

Resolution

To enable LLDP information display, you must ensure the Distributed Switches are configured correctly.

Update Distributed Switch Properties

1. Navigate to the Networking view in vCenter.

2. Select your Distributed Switch.

3. Select the Configure tab.

4. Under Settings, click Properties and click Edit.

5. Click on Advanced and change the Discovery Protocol dropdown to Link Layer Discovery Protocol.

6. Click OK.

Additional Information

Reference: Enable Link Layer Discovery Protocol on a vSphere Distributed Switch
Reference: Unable to see LLDP information on ESXi hosts using Intel X710 (or any Intel 700 series) adapters with the i40en device driver