CCNA: LLDP VS CDP DISCOVERY PROTOCOL UNDERSTANDING & LAB

CCNA: LLDP VS CDP DISCOVERY PROTOCOL UNDERSTANDING & LAB

Network Lab kbraut   June 10, 2024

Cisco Discovery Protocol (CDP):

Overview: A Cisco proprietary network protocol. Information about Cisco devices that are directly connected is shared via it. It is exclusive to Cisco equipment and functions similarly to LLDP. It works over the OSI model's L2 (data link layer). By default, on Cisco hardware, enabled.

Important CDP Features

• Cisco-Specific
• Information Sharing
• Topology Discovery
• Device Management

 Link Layer Discovery Protocol (LLDP)

Overview: On a local network, network devices can advertise their identities, capabilities, and neighbors using LLDP, a vendor-neutral Layer 2 discovery protocol. It runs over the OSI model's L2 (data link layer), as defined by the IEEE 802.1AB standard.

Important LLDP Features

• Vendor-Neutral
• Information Exchange
• Topology Discovery
• Automated Configuration

Note: CDP is Cisco proprietary protocol, CDP is enabled on Cisco
devices by default. No need to enable it. 

Verification Commands 

Switch1#show cdp

Switch1#show cdp neighbors

Switch1#show cdp neighbors detail 

Switch1#show cdp interface 

Change CDP timers to 45 sec and holdtime to 60 sec (this command only supports real ISO Devices)

Siwtch1#config t

Siwtch1(config)#cdp timer 45

Siwtch1(config)#cdp holdtime 60

Verification Commands 

Switch1#show cdp

Disable CDP Globally or on an Interface Basis.

Switch1#config t

Switch1(config)#no cdp run

Switch1(config)#exit

Switch1#

Or

Switch1#config t

Switch1(config)#interface range fa0/1, fa0/2

Switch1(config-if)#no cdp enable

Switch1(config-if)#exit

Switch1(config)#exit

Switch1#

LLDP (Link Layer Discovery Protocol)

Note: The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link layer

protocol and we need to manually enable it on a network device

Configuration:

Switch1#config t

Switch1(config)#lldp run

Switch1(config)#exit

Switch1#

Verification Commands 

Switch1#show lldp 

Switch1#show lldp neighbors

Switch1#show lldp neighbors detail 

Change LLDP timers to 15 sec and holdtime to 30 sec 

Configuration:

Switch1#config t

Switch1(config)#lldp timer 15

Switch1(config)#lldp holdtime 30

Switch1(config)#exit

Switch1#

Disable LLDP globally or on interface basis.

Switch1#config t

Switch1(config)#no lldp run

Switch1(config)#exit

Switch1#

Or

Switch1#config t

Switch1(config)#interface range fa0/0, fa0/1

Switch1(config-if-range)#no lldp transmit

Switch1(config-if-range)#no lldp receive

Switch1(config-if-range)#exit

Switch1(config)#exit

Switch1#

Important Commands:

sh cdp

sh cdp neighbors

sh cdp neighbors details

sh cdp interface 

sh lldp

sh lldp neighbors

sh lldp neighbors detail

sh lldp interface fa x/x

CCNA Lab Implement Inter-VLAN Routing

CCNA Lab Implement Inter-VLAN Routing

Network Lab kbraut   June 02, 2024

Network Topology: 

"Router on a stick" is a network configuration where a single router is connected to a switch via one physical interface but can manage multiple VLANs (Virtual Local Area Networks). In this scenario we used VLAN10 and VLAN20 for different groups for different purpose. 

This setup allows the router to route traffic between VLANs on the switch, acting as a gateway for inter-VLAN communication.

Objectives

• Build the network and configuration basic Cisco Router
• Configuration Gateway for all vlan at Router
• Creating VLANs 
• Configuration Trunking / Access at Switch Layer 2 

Step 1: In first setup, Cisco Router question to you about initial configuration dialog. You should be type “no” bypass this step

Step 2: You must be basic configuration for Router as following 

Commands	Details
Router>	User mode
Router> enable	Moving to Privilege mode
Router# configuration terminal	Moving to global config
Router(config)# hostname R1	Config hostname from Router to R1
R1 (config)# banner motd #This is Router #	Config banner message
R1 (config)# enable password   cisco123enable	Set password login from user mode to Privilege mode
R1 (config)# service password-encryption	Request Router use service password encryption
R1 (config)# line con 0	Configuration line console
R1 (config-line)# password ccna	Set password login from console
R1 (config-line)# login	Apply password into line console
R1 (config-line)# exit	Exit configuration line console
R1 (config)# line vty 0 4	Configuration line vty
R1 (config-line)# transport in all	Set method access into router via line vty
R1 (config-line)# password telnet	Set password login from live vty
R1 (config-line)# login	Apply password on line vty
R1 (config-line)# exit	Exit configuration line vty

                                

                                                     

Step 3: IP Configuration for R1                                              

Commands	Details
R1 (config)#	Privilege mode
R1 (config)# interface gi0/0/1	Configuration interface eth (eth-mode)
R1 (config-if)# description Connectio-to-SW1	Add a description on interface
R1 (config-if)# no shutdown	Active interface
R1 (config-if)# exit	Exit interface
R1 (config)# interface gi0/0/1.10	Configuration sub interface
R1 (config-if)# description Connection-to-VLAN-10	Add a description on sub interface
R1 (config-if)# encapsulation dot1Q 10	Set Sub-interface working with VLAN10
R1 (config-if)# ip address 10.10.10.1 255.255.255.0	Set ip address for sub interface
R1 (config-if)# no shutdown	Active interface
R1 (config-if)# exit	Exit sun interface
R1 (config)# interface gi0/0/1.20	Configuration sub interface
R1 (config-if)# description Connection-to-VLAN-20	Add a description on sub interface
R1 (config-if)# encapsulation dot1Q 20	Set Sub-interface working with VLAN20
R1 (config-if)# ip address 10.10.20.1 255.255.255.0	Set ip address for sub interface
R1 (config-if)# no shutdown	Active sub interface
R1 (config-if)# exit	Exit configuration
R1 (config)# write	Save running-config to startup-config

tep 4: Verify configuration on R1

• Type command “show ip int brief” and enter

• Type command “show running-config” and enter

• Type command “show running-config | include interface GigabitEthernet0/0/1” and enter

Step 5: Configuration for Switch:

Commands	Details
Switch> enable	moving to Privilege mode
Switch#	Privilege mode
Switch# configuration terminal	moving to global config
Switch(config)#no ip domain-lookup	tells the SW not to search any wrong words typed in the CLI.
Switch(config)#vlan 10	add vlan 10
Switch(config-vlan)#name Grp10	Set description
Switch (vlan)# exit	exit vlan mode
Switch(config)#vlan 20	add vlan 10
Switch(config-vlan)#name Grp20	Set description
Switch (vlan)# exit	exit vlan mode

Step 6: Verify VLAs: 

• Type command “show vlan” and enter

Step 7: Configuration SW Uplink Port as a Trunk:

Commands	Details
Switch# configuration terminal	Moving to global config
Switch (config)# interface fa0/1	Configuration interface ethernet
Switch (config)# description Connection-to-Router	Add a description on interface
Switch(config-if)#switchport mode trunk	Set interface working with trunk mode
Switch(config-if)#switchport trunk allowed vlan 10,20	Set Vlans 10,20 into interface as a Trunk

 

• Type command “show interfaces trunk” and enter

Step 8: Configuration SW Down Link as an Access for end device 

Commands	Details
Switch (config)# interface fa 0/2	Configuration interface ethernet
Switch (config-if)# description Connection-to-VLAN10	Add a description on interface
Switch (config-if)# switchport mode access	Set interface working with access mode
Switch (config-if)# switchport access vlan 10	Set Vlan 10 into interface
Switch (config-if)# exit	Exit config interface mode
Switch (config)# interface fa 0/3	Configuration interface ethernet
Switch (config-if)# description Connection-to-VLAN20	Add a description on interface
Switch (config-if)# switchport mode access	Set interface working with access mode
Switch (config-if)# switchport access vlan 20	Set Vlan 20 into interface
Switch (config-if)# exit	Exit config interface mode
Switch(config)#do write	Save running-config to startup-config

 

Step 9: Verify VLAN Port Access  

• Type command “show vlan” and enter