Configuring LLDP on Cisco Devices

Objective

The objective of this lab exercise is for you to learn and understand how to enable the LLDP protocol on a Cisco Network.

Purpose

Configuring and applying the Link Layer Discovery Protocol (LLDP) allows network devices to discover other network devices directly connected to them. This is a fundamental skill that provides the same benefits as CDP but is also compatible with non-Cisco equipment. As a Cisco engineer, as well as in the Cisco CCNA exam, you will be expected to know how to enable LLDP in your network.

Lab Topology

Use the following topology to complete this lab exercise:

Task 1: Configure Hostnames

Objective: Configure the hostnames on R1 and R2 as illustrated in the topology.

Configuration:

Router#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#hostname R1
R1(config)#

Router#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#hostname R2
R2(config)#

Task 2: Configure IP Addresses

Objective: Configure the IP addresses on the Ethernet interfaces of R1 and R2 as illustrated in the topology. There is no need to configure the Loopback interfaces for this lab.

Configuration:

R1#conf t
Enter configuration commands, one per line. End with CTRL/Z.
R1(config)#int fa0/0
R1(config-if)#ip address 192.168.1.1 255.255.255.0
R1(config-if)#no shut

R2#conf t
Enter configuration commands, one per line. End with CTRL/Z.
R2(config)#int fa0/0
R2(config-if)#ip address 192.168.1.2 255.255.255.0
R2(config-if)#no shut

Task 3: Disable CDP and Enable LLDP

Objective: Disable CDP globally on both routers and enable LLDP (it’s disabled by default).

Configuration:

R1#conf t
Enter configuration commands, one per line. End with CTRL/Z.
R1(config)#no cdp run
R1(config)#lldp run
R1(config)#end
R1#copy running-config startup-config

R2#conf t
Enter configuration commands, one per line. End with CTRL/Z.
R2(config)#no cdp run
R2(config)#lldp run
R2(config)#end
R2#copy running-config startup-config 

Task 4: Verify LLDP Neighbors

Objective: Ensure that both R1 and R2 have found each other via their Ethernet links using LLDP.

Configuration:

R1#show lldp neighbors
Capability codes:
    (R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device
    (W) WLAN Access Point, (P) Repeater, (S) Station, (O) Other
Device ID           Local Intf     Hold-time  Capability      Port ID
R2                  Fa0/0          120        R               Fa0/0

Total entries displayed: 1

R2#show lldp neighbors
Capability codes:
    (R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device
    (W) WLAN Access Point, (P) Repeater, (S) Station, (O) Other
Device ID           Local Intf     Hold-time  Capability      Port ID
R1                  Fa0/0          120        R               Fa0/0

Total entries displayed: 1

Task 5: Disable LLDP on an Interface

Objective: Disable one of the interfaces to prevent it from sending LLDP traffic.

Configuration:

R1(config)#int fa0/1
R1(config-if)#no lldp transmit

Cisco Packet Tracer file:
Load and open the .pkt Lab file in Cisco Packet Tracer from here: Configuring_LLDP_on_Cisco_Devices.pkt