CDP Settings on the SG350XG and SG550XG

Objective

The Cisco Discovery Protocol (CDP) is a protocol that is used by Cisco devices to share device information with other connected Cisco devices. This includes type of device, firmware version, IP address, serial number, and other identifying information. CDP settings can be adjusted globally or on an individual port basis on the SG350XG and SG550XG series switches.

The objective of this document is to show you how to configure global and individual CDP settings on the SG350XG and SG550XG.

Applicable Devices

• SG350XG
• SG550XG

Software Version

• v2.0.0.73

CDP Settings

Global Properties

Step 1. Log in to the web configuration utility and choose Administration > Discovery – CDP > Properties. The Properties page opens.

Step 2. In the CDP Status field, check the Enable checkbox to activate CDP on the switch. If you are using the Basic display mode, skip to Step 14. If you enabled CDP, skip to Step 4.

Note: The display mode can be changed using the drop-down list in the top-right corner of the web utility.

Step 3. In the CDP Frames Handling field, select a radio button corresponding to the action you want the switch to take when it receives a CDP packet. This field is only available if CDP is not enabled on the switch. After selecting an option, skip to Step 11.

The options are:

• Bridging – Forward the packet based on the VLAN.
• Filtering – Delete the packet.
• Flooding – Forwards all CDP packets to all ports, excluding the port it originated from.

Step 4. In the CDP Voice VLAN Advertisement field, check the Enable checkbox to have the switch advertise the voice VLAN over CDP on all ports that have CDP enabled and are members of the voice VLAN.

Step 5. In the CDP Mandatory TLVs Validation field, check the Enable checkbox to discard incoming CDP packets that do not contain the mandatory TLV (type-length-value).

Step 6. In the CDP Version field, select a radio button to choose which version of CDP to use (Version 1 or Version 2).

Step 7. In the CDP Hold Time field, select a radio button to determine the amount of time CDP packets are held before being discarded. Select Use Default to use the default amount of time (180 seconds) or User Defined to specify a custom amount of time between 10 – 255 seconds.

Step 8. In the CDP Transmission Rate field, select a radio button to determine the transmission rate of CDP packets in seconds. Select Use Default to use the default amount of time (60 seconds) or User Defined to specify a custom amount of time between 5 – 254 seconds.

Step 9. In the Device ID Format field, select a radio button to determine what the format of the device ID will be. Select MAC Address to use the switch’s MAC address as the device ID, Serial Number to use the serial number, or Hostname to use the hostname.

Step 10. In the Source Interface field, select a radio button to determine what IP address will be put in the TLV field of outgoing CDP packets. Select Use Default to use the IP address of the outgoing interface, or User Defined to choose an interface (the selected interface’s IP address will be used) from the drop-down lists in the Interface field.

Step 11. In the Syslog Voice VLAN Mismatch field, check the Enable checkbox to send a syslog message when a voice VLAN mismatch is detected. A VLAN mismatch is when VLAN information in an incoming frame does not match the local device’s advertised capabilities.

Step 12. In the Syslog Native VLAN Mismatch field, check the Enable checkbox to send a syslog message when a native VLAN mismatch is detected.

Step 13. In the Syslog Duplex Mismatch field, check the Enable checkbox to send a syslog message when a duplex mismatch is detected.

Step 14. Click Apply.

Interface Properties

Step 1. Log in to the web configuration utility and choose Administration > Discovery – CDP > Interface Settings. The Interface Settings page opens.

Note: This page is only available in advanced display mode. The display mode can be changed with the drop-down list in the top right corner of the web utility.

Step 2. In the CDP Interface Settings Table, select the radio button of the interface you want to configure and click the Edit… button. The Edit CDP Interface Settings window opens.

Note: If the switch is part of a stack, you can display the interfaces of other units in the stack by using the drop-down list at the top of the table.

Step 3. The Interface field displays the port selected in the CDP Interface Settings Table. You can use the Unit and Port drop-down lists to select another unit and port to configure, respectively.

Step 4. In the CDP Status field, check the Enable checkbox to enable CDP on the port specified.

Step 5. In the Syslog Voice VLAN Mismatch field, check the Enable checkbox to send a syslog message when a voice VLAN mismatch is detected on the port specified. A VLAN mismatch is when VLAN information in an incoming frame does not match the local device’s advertised capabilities.

Step 6. In the Syslog Native VLAN Mismatch field, check the Enable checkbox to send a syslog message when a native VLAN mismatch is detected on the port specified.

Step 7. In the Syslog Duplex Mismatch field, check the Enable checkbox to send a syslog message when a duplex mismatch is detected on the port specified.

Step 8. Click Apply. The changes will be applied to the port specified. You can use the Interface field to configure another port without returning to the Interface Settings page.

Step 9. To quickly copy a port’s settings to another port or ports, select its radio button and click the Copy Settings… button. The Copy Settings window opens.

Step 10. In the text field, enter the port or ports (separated by commas) that you want to copy the specified port’s settings to. You can also enter a range of ports.

Step 11. Click Apply. The settings are copied.