Link Layer Discovery Protocol (LLDP) Media Endpoint Discovery (MED) provides additional capabilities to support media endpoint devices such as to enable the advertisement of network policies for applications like voice or video, device location discovery, and troubleshooting information. LLDP and Cisco Discovery Protocol (CDP) are both similar protocols, and the difference is that LLDP facilitates vendor interoperability and CDP is Cisco proprietary.
LLDP can be used in scenarios where you need to work between devices which are not Cisco proprietary and devices which are Cisco proprietary. You can use the LLDP protocol for troubleshooting purposes. The switch gives all the information about the current LLDP status of ports and you can use this information to fix connectivity problems within the network.
This article provides instructions on how to configure the LLDP properties on the switch.
Note: To learn how to configure the LLDP properties of your switch through the web-based utility, click here.
Step 1. Log in to the switch console. The default username and password is cisco. If you have configured a new username or password, enter the credentials instead.
Note: In this example, the SG350X switch is accessed through Telnet.
Step 2. In the Privileged EXEC mode of the switch, enter the Global Configuration context by entering the following:
Step 3. To globally enable the LLDP feature on the switch, enter the following:
SG350X(config)#lldp runNote: LLDP is globally enabled by default.
Step 4. (Optional) To globally disable the LLDP feature, enter the following:
SG350X(config)#no lldp runStep 5. (Optional) To define the LLDP packet handling when LLDP is globally disabled, enter the following:
SG350X(config)#lldp lldpdu [filtering | flooding]The options are:
Note: In this example, flooding is entered.
Note: LLDP packets are filtered when LLDP is globally disabled.
If LLDP is globally disabled, and the LLDP packet handling mode is flooding, LLDP packets are treated as data packets with the following exceptions:
Step 6. To configure the maximum transmission rate of LLDP notifications, enter the following:
SG350X(config)#lldp notifications interval [seconds]Note: In this example, the interval used is 360 seconds.
Step 7. (Optional) To return the maximum transmission rate of LLDP notifications to the default setting, enter the following:
SG350X(config)#no lldp notifications intervalStep 8. To specify how often the software sends LLDP updates, enter the following:
SG350X(config)#lldp timer [seconds]Note: In this example, the timer used is 60 seconds.
Step 9. (Optional) To restore the default LLDP timer configuration, enter the following:
SG350X(config)#no lldp timerStep 10. To specify how long the receiving device holds an LLDP packet before discarding it, enter the following:
SG350X(config)#lldp hold-multiplier [number]Note: In this example, the hold multiplier value is set to 5.
Step 11. (Optional) To return the maximum transmission rate of LLDP notifications to the default setting, enter the following:
SG350X(config)#no lldp hold-multiplierStep 12. To specify the minimum time an LLDP port waits before reinitializing LLDP transmission, enter the following:
SG350X(config)#lldp reinit [seconds]Note: In this example, the reinitializing LLDP transmission time is set to 3 seconds.
Step 13. (Optional) To revert the reinitializing LLDP transmission configuration setting on your switch, enter the following:
SG350X(config)#no lldp reinitStep 14. To configure the amount of time that passes between successive LLDP frame transmissions due to changes in the LLDP local systems MIB, enter the following:
SG350X(config)#lldp tx-delay [seconds]Note: In this example, the transmission delay is set to 15 seconds.
Step 15. (Optional) To return the transmit delay values to the default configuration, enter the following:
SG350X(config)#no lldp tx-delayStep 16. (Optional) To configure the source of the chassis ID advertisement in the LLDP messages, enter the following:
SG350X(config)#lldp chassis-id [mac-address | host-name]The options are:
Note: In this example, host-name is used.
Step 17. (Optional) To restore the chassis ID source to the default configuration, enter the following:
SG350X(config)#no lldp chassis-idStep 18. When a port comes up, LLDP can send packets more quickly than usual using its fast start mechanism. To configure the number of packets that is sent during the activation of the fast start mechanism, enter the following:
SG350X(config)#lldp med fast-start repeat-count [number]Note: In this example, the repeat count number is set to 5.
Step 19. (Optional) To return the repeat counter to the default setting, enter the following:
SG350X(config)#no lldp med fast-start repeat-countStep 20. Enter the exit command to go back to the Privileged EXEC mode of the switch.
SG350X#exitStep 21. (Optional) In the Privileged EXEC mode of the switch, save the configured settings to the startup configuration file, by entering the following:
SG350X#copy running-config startup-configStep 22. (Optional) Press Y for Yes or N for No on your keyboard once the Overwrite file [startup-config]… prompt appears.
Note: In this example, Y is pressed.
You should now have successfully configured the global LLDP properties on your switch through the CLI.
To learn how to configure the LLDP settings on specific ports on your switch through the web-based utility, click here for instructions. For CLI-based instructions, click here.
Step 1. In the Privileged EXEC mode of the switch, enter the following to display the global LLDP configuration settings:
SG350X#show lldp configuration [interface-id | detailed]The options are:
Note: In this example, detailed LLDP configuration is displayed.
The LLDP configuration displays the following information:
- PD — Port description
- SN — System name
- SD — System description
- SC — System capabilities
You should now have displayed the configured LLDP settings on your switch through the CLI.
Revision | Publish Date | Comments |
---|---|---|
1.0 |
13-Dec-2018 |
Initial Release |