Switch discovery protocols allow vSphere administrators to determine which physical switch port is connected to a given vSphere standard switch or vSphere distributed switch. Its make us easy to troubleshooting network connectivity issues means we can quickly find the physical switch Port/IP/VLAN etc. below is sample screen shot.
Cisco Discovery Protocol (CDP) is limited to Cisco switches only. It is available in both vSphere standard switches (vSS) and vSphere distributed switches (vDS).
Link Layer Discovery Protocol (LLDP) in not limited to any specific vender devices it’s for every one.it is available only in vSphere distributed switches (vDS) with version 5.0.0 and later.
Both CDP/LDP can be configured on different “operational modes”.
Listen – This is default operational mode in vmware. ESXi detects and displays information from connected physical switch port, but all information of virtual switch is not available to the physical switch.
Advertise – it do the opposite as listen mode does. Means ESXi send information of virtual switch to the connected physical switch, but doesn’t receive any information of physical switch port
Both – Does both advertise and listen.
1-CDP Configuration on vSS
I did not find any configuration to disable or change the operational mode of discovery protocol using GUI. However you do this with “esxcli” command.
To disable CDP on vSwitch0
#esxcli network vswitch standard set -c down -v vSwitch0
NOTE: Operation Mode ‘down’, ‘listen’, ‘advertise’ or ‘both can be set using esxcli.
2- Configure CDP/LLDP on vDS.
By default CDP is enabled on vDS and is listening mode. You can change it to LLDP if you want to.
To change the discovery protocol using webclient. Select you vDS -> Manage -> Settings -> Properties -> Click “Edit”
In “advanced” – you change discovery protocol type into (CDP/LLDP/disabled) -> Click “OK”
You can also change the “operation mode” of discovery protocol in the advance setting of vDS as shown below.