Cisco Cisco SG300-28 28-Port Gigabit Managed Switch Maintenance Manual

Configuring CDP

Cisco Small Business 200, 300 and 500 Series Managed Switch Administration Guide (Internal Version) 

155

 

Similar to LLDP, CDP (Cisco Discovery Protocol) is a link layer protocol for directly 
connected neighbors to advertise themselves and their capabilities to each other. 
Unlike LLDP, CDP is a Cisco proprietary protocol.

The followings is sample workflow in configuring CDP on the device. You can also 
find additional CDP configuration guidelines in the LLDP/CDP section.

Enter the CDP global parameters using the CDP Properties page

Configure CDP per interface using the Interface Setting page

If Auto Smartport is to detect the capabilities of CDP devices, enable CDP in the 
Smartport Properties page.

See 

 for a description of how CDP is used to identify 

devices for the Smartport feature.

To enter CDP general parameters:

Click Administration > Discovery - CDP > Properties.

Enter the parameters.

•

CDP Status—Select to enable CDP on the device.

•

CDP Frames Handling—If CDP is not enabled, select the action to be taken 
if a packet that matches the selected criteria is received:

-

Bridging

—Forward the packet based on the VLAN.

-

Filtering

—Delete the packet.

-

Flooding

—VLAN unaware flooding that forwards incoming CDP packets 

to all the ports excluding the ingress ports. 

•

CDP Voice VLAN Advertisement—Select to enable the device to advertise 
the voice VLAN in CDP on all of the ports that are CDP enabled, and are 
member of the voice VLAN. The voice VLAN is configured in the Voice VLAN 
Properties page.

•

CDP Mandatory TLVs Validation—If selected, incoming CDP packets not 
containing the mandatory TLVs are discarded and the invalid error counter is 
incremented.