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CDP & LLDP Questions

March 16th, 2020 Go to comments
CDP Quick Summary

Cisco Discovery Protocol (CDP) is a Layer 2 protocol that runs on Cisco devices and enables networking applications to learn about directly connected devices nearby. The information contained in Cisco Discovery Protocol advertisements varies based on the type of device and the installed version of the operating system. Some of the information that Cisco Discovery Protocol can learn includes:
+ Cisco IOS version running on Cisco devices
+ Hardware platform of devices
+ IP addresses of interfaces on devices
+ Locally connected devices advertising Cisco Discovery Protocol
+ Interfaces active on Cisco devices, including encapsulation type
+ Hostname
+ Duplex setting
+ VLAN Trunking Protocol (VTP) domain
+ Native VLAN

Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/cdp/configuration/15-mt/cdp-15-mt-book/nm-cdp-discover.html

LLDP Quick Summary

Link Layer Discovery Protocol (LLDP) is a industry standard protocol that allows devices to advertise, and discover connected devices, and there capabilities (same as CDP of Cisco). To enable it on Cisco devices, we have to use this command under global configuration mode:

Sw(config)# lldp run

Question 1

Question 2

Explanation

Although CDP is a Layer 2 protocol but we can check the neighbor IP address with the “show cdp neighbor detail” command. If the neighbor does not has an IP address then CDP still operates without any problem. But the IP address of that neighbor is not provided.

Question 3

Explanation

+ lldp holdtime seconds: Specify the amount of time a receiving device should hold the information from your device before discarding it
+ lldp reinit delay: Specify the delay time in seconds for LLDP to initialize on an interface
+ lldp timer rate: Set the sending frequency of LLDP updates in seconds

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_55_se/configuration/guide/3560_scg/swlldp.html

Question 4

Explanation

Link Layer Discovery Protocol (LLDP) is a industry standard protocol that allows devices to advertise, and discover connected devices, and there capabilities (same as CDP of Cisco). To enable it on Cisco devices, we have to use this command under global configuration mode:

Sw(config)# lldp run

Question 5

Question 6

Explanation

+ lldp holdtime seconds: Specify the amount of time a receiving device should hold the information from your device before discarding it
+ lldp reinit delay: Specify the delay time in seconds for LLDP to initialize on an interface
+ lldp timer rate: Set the sending frequency of LLDP updates in seconds

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_55_se/configuration/guide/3560_scg/swlldp.html

Comments (2) Comments
  1. Raja
    August 25th, 2020

    Questions are not showing…?

  2. Sumi
    August 27th, 2020

    @raja go for preminum account

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