Practice Labs

Get started with Practice Labs — 30+ hands-on labs built to strengthen your CCNA skills through focused, deliberate practice. Each lab pairs topic-based tests with ready-to-use Packet Tracer files, helping you apply core networking concepts and build real-world, exam-ready confidence.

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IP Addressing

Topic Overview

An IP address allows devices to communicate over a network. Each device in a network is assigned a unique identifier called an IP address. IP addresses can be classified into two versions:

IPv4: A 32-bit address written in dotted decimal format (e.g., 192.168.1.1).
IPv6: A 128-bit address written in hexadecimal notation separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).

IP addresses are divided into:

Network Address: Identifies the network.
Host Address: Identifies the device within the network.

Subnetting

Subnetting divides a large network into smaller, manageable sub-networks (subnets). This is done by extending the network portion of an IP address using a subnet mask.

Default Subnet Masks:

Class A: 255.0.0.0

Class B: 255.255.0.0

Class C: 255.255.255.0

CIDR (Classless Inter-Domain Routing) is commonly used to represent subnets in the format /n (e.g., 192.168.1.0/24).

Some Useful Commands to remember:

Assigning an IP Address to an Interface:

Router(config)# interface <interface_id>

Router(config-if)# ip address <ip_address> <subnet_mask>

Assigns IPv4 address to the interface.

Router(config-if)# ipv6 address <ip_address>/<prefix length>

Assigns IPv6 address to the interface.

Router(config-if)# no shutdown

Enables/Disables the interface.

Viewing IP Configuration:

Router# show ip interface brief

Displays a summary of IP addresses and interface status.

Router# show running-config

Shows the current configuration, including IP addresses on interfaces.

Testing Connectivity:

Router# ping <ip_address>

Verifies connectivity with a specific IP address.

Router# traceroute <ip_address>

Displays the path packets take to reach the destination.

Included Labs

IPv4 and IPv6 Addressing 1

IPv4 and IPv6 Addressing 2

IPv4 Subnetting 1

VLAN and Trunking

Topic Overview

Virtual Local Area Networks (VLANs) and trunking are used to logically segment networks and facilitate communication between these segments.

VLAN (Virtual Local Area Network)

A VLAN is a logical grouping of devices in a LAN (Local Area Network) that are treated as if they are on the same physical network, even if they are spread across different physical devices or locations. VLANs allow network segmentation to improve performance, enhance security, and simplify management.

VLANs Types:

Default VLAN: VLAN 1 is used as default VLAN on Cisco switches; used for management traffic by default.
Reserved VLANs: VLAN 1001 – 1005 are reserved for various protocols.
Other VLANs: Custom VLANs (e.g., VLAN 10, VLAN 20) can be created for user traffic.

Trunking

A trunk is a point-to-point link between network devices (usually switches or routers) that carries traffic for multiple VLANs. Trunking enables inter-VLAN communication across a network.

Trunking Protocols:

ISL: A Cisco proprietary protocol; not used in modern networks.

IEEE 802.1Q: The standard protocol used for VLAN tagging on trunk links. It adds a 4-byte VLAN tag to Ethernet frames to identify the VLAN.

Some Useful Commands to remember:

VLAN Configuration Commands:

Creating and Naming a VLAN:

Switch(config)# vlan <vlan_id>

Switch(config-vlan)# name <vlan_name>

Assigning an Interface to a VLAN:

Switch(config)# interface <interface_id>

Switch(config-if)# switchport mode access

Switch(config-if)# switchport access vlan <vlan_id>

Verifying VLAN Configuration:

Switch# show vlan brief

Trunk Configuration Commands:

Configuring a Trunk Port:

Switch(config)# interface <interface_id>

Switch(config-if)# switchport mode trunk

Switch(config-if)# switchport trunk allowed vlan <vlan_id_range>

Setting the Native VLAN (Untagged Traffic):

Switch(config-if)# switchport trunk native vlan <vlan_id>

Verifying Trunk Configuration:

Switch# show interfaces trunk

Included Labs

VLAN and Trunking 1

Voice VLAN Configuration 1

VLAN and Trunking 2

LACP

Topic Overview

Link Aggregation Control Protocol (LACP) is a standardized protocol (defined in IEEE 802.3ad) that combines multiple physical links into a single logical link to provide redundancy and increase bandwidth. This process is called EtherChannel on Cisco devices.

Modes of LACP

LACP has two modes:

Active: Actively initiates LACP negotiations.
Passive: Waits for the other side to initiate the negotiation.

Key Rule:

LACP aggregation occurs only when:

One side is active and the other is active or passive.
Two passive sides will not form a link aggregation.

Some Useful Commands to remember:

LACP Configuration:

Configuring the Physical Interfaces to form the EtherChannel.

Switch(config)# interface range <f0/1 - 3>
Switch(config-if-range)# channel-group <group_number> mode {active | passive}

Configuring the EtherChannel interface:

Switch(config)# interface port-channel <group number>

Verification and Troubleshooting:

Verify LACP Configuration.

Switch# show etherchannel

View Detailed LACP Information.

Switch# show lacp neighbor

Check EtherChannel Status.

Switch# show interfaces port-channel <channel_number>

Debug LACP Issues.

Switch# debug lacp events

Included Labs

LACP configuration 1

LACP configuration 2

LACP configuration 3

CDP and LLDP

Topic Overview

Cisco Discovery Protocol (CDP):
CDP is a Cisco proprietary Layer 2 protocol used to share information about directly connected Cisco devices, such as device ID, IP address, port details, and device capabilities.

Link Layer Discovery Protocol (LLDP):
LLDP is a vendor-neutral Layer 2 protocol standardized in IEEE 802.1AB. It is used to discover and advertise information between adjacent devices, such as device type, software version, and management IP.

Modes of Operation:

CDP: Enabled globally and on interfaces by default on Cisco devices.
LLDP: Must be enabled explicitly on Cisco devices as it is disabled by default.

Key Rules:

CDP works only on Cisco devices.
LLDP allows interoperability between different vendors.
If CDP or LLDP is disabled globally on a device, it can’t be enabled on a specific interface.

Some Useful Commands to remember:

CDP Configuration:

Enable/Disable CDP globally:

Switch(config)# cdp run
Switch(config)# no cdp run

Enable/Disable CDP on specific interfaces:

Switch(config)# interface <interface_id>
Switch(config-if)# cdp enable
Switch(config-if)# no cdp enable

LLDP Configuration:

Enable/Disable LLDP globally:

Switch(config)# lldp run
Switch(config)# no lldp run

Enable/Disable LLDP on specific interfaces:

Switch(config)# interface <interface_id>
Switch(config-if)# lldp transmit
Switch(config-if)# lldp receive
Switch(config-if)# no lldp transmit
Switch(config-if)# no lldp receive

Verification and Troubleshooting:

Verify CDP Neighbors:

Switch# show cdp neighbors

View Detailed CDP Neighbor Information:

Switch# show cdp neighbors detail

Verify LLDP Neighbors:

Switch# show lldp neighbors

View Detailed CDP Neighbor Information:

Switch# show lldp neighbors detail

Included Labs

CDP and LLDP configuration 1

CDP and LLDP configuration 2

CDP and LLDP configuration 3

Static Routing