Networking
Course Overview

The complete course to help you prepare and pass
Cisco's newest CCNA 200-301 exam.

Go to course

Why get Cisco certified?

Certified employees are valued assets.

  • Obtain the Official Stamp.

    It is an official stamp from trusted industry leaders that you know what you claim to know – be it entry, intermediate, or expert level.

  • Show Your Relevance.

    Certification is a way of saying to your future boss that you know the correct information.

  • Employers Prefer Certified Candidates.

    The International Data Corporation led a survey of hiring managers and reported that 75% believe that certified employees perform better than those without certification.

How to certify?

There are no formal prerequisites for CCNA certification, but you should have
an understanding of the exam topics before taking the exam.

Review exam topics.

Now let's come back to the Course Overview

All the topics for CCNA certification cover in this course.

  1. Download and Install Recommended Software
  2. Basic Networking Terms
  3. TCP/IP & OSI Models
  4. IP Addressing
  5. Initial Device Configuration
  6. IP Subnetting
  7. Cabling and Packet Flows
  8. What is loopback?
  9. TCP vs. UDP
  10. Wireshark Introduction
  11. VLANs & 802.1Q
  12. Spanning Tree
  13. BPDU Guard
  14. Cisco Discovery Protocol (CDP)
  15. IP Routing
  16. Dynamic Host Configuration Protocol (DHCP)
  17. Domain Name System (DNS)
  18. Variable Length Subnet Mask (VLSM)
  19. Network Time Protocol (NTP)
  20. Port Mirroring (SPAN)

Network Simulation Software

The two software have been designed to address different needs.

Cisco Packet Tracer vs. GNS3

  • Cisco Packet Tracer

    A network simulator and embeds only limited real equipment features.

  • GNS3

    A network emulator based on Dynamips and QEMU running real IOS images, virtual machines...

Basic Networking Terms

What is a Network?

A network is defined as a group of two or more computer systems linked together.

Most basic type of network:

Local Area Network (LAN) Wide Area Network (WAN)

You need understanding:

Servers Clients Ports Protocols

Networking Devices

Repeaters Hubs Switches Routers Firewalls

TCP/IP vs. OSI

Key Difference

  • OSI has 7 layers whereas TCP/IP has 4 layers.
  • The OSI Model is a logical and conceptual model that defines network communication used by systems open to interconnection and communication with other systems.
  • On the other hand, TCP/IP helps you to determine how a specific computer should be connected to the internet and how you can be transmitted between them.
  • OSI header is 5 bytes whereas TCP/IP header size is 20 bytes.
  • OSI refers to Open Systems Interconnection whereas TCP/IP refers to Transmission Control Protocol.
  • OSI follows a vertical approach whereas TCP/IP follows a horizontal approach.
  • OSI model, the transport layer, is only connection-oriented whereas the TCP/IP model is both connection-oriented and connectionless.
  • OSI model helps you to standardize router, switch, motherboard, and other hardware whereas TCP/IP helps you to establish a connection between different types of computers.

IP Addressing

What is an IP Address?

An IP address is a number identifying of a computer or another device on the Internet.

Network and Host addresses

An IP address consists of two components: the network address and the host address.
The network address is used to find the subnet in which the computer or the device is located
and the host address is used to find the computer or the device in the subnet.

You need to know:

IP Address Classes IPv4 Special-Purpose Addresses Subnet Mask

Initial Device Configuration

Initial device configuration is necessary when first powering on a new router or switch.
It can be accomplished through the System Configuration Dialog guide or manually.

Want to know how to configure?

Configuration Steps

IP Subnetting

What is Subnetting?

Subnetting is the process of stealing bits from the HOST part of an IP address
in order to divide the larger network into smaller sub-networks called subnets.

Reasons to Subnet

  1. Improved Network Security
  2. Better Network Performance and Speed
  3. Administration is a Breeze
  4. Easier to Control Growth of Network
  5. Less Network Congestion

How to Subnet?

Subnetting in Binary Subnetting in Decimal (Fast Way)

Cabling and Packet Flows

What are the types of communication?

Unicast Broadcast Multicast

You need understanding:

Bus Topology 10base2, 10base5, 10baseT Cable Types and Specifications Differences between a network hub, switch, and router Half duplex and Full duplex

Loopback

The loopback device is a special, virtual network interface that your computer uses to communicate with itself.
It is used mainly for diagnostics and troubleshooting, and to connect to servers running on the local machine.

Want to know more about Loopback Interface?

Click Here

TCP vs. UDP

Key Difference

  • TCP is a connection-oriented protocol, whereas UDP is a connectionless protocol.
  • The speed for TCP is slower while the speed of UDP is faster.
  • TCP uses handshake protocol like SYN, SYN-ACK, ACK while UDP uses no handshake protocols.
  • TCP does error checking and also makes error recovery, on the other hand, UDP performs error checking, but it discards erroneous packets.
  • TCP has acknowledgment segments, but UDP does not have any acknowledgment segment.
  • TCP is heavy-weight, and UDP is lightweight.

Wireshark Introduction

Wireshark is the world’s foremost and widely-used network protocol analyzer.

Want to know how to use it? Watch tutorial below:

VLANs & 802.1Q

What is VLANs?

A custom network which is created from one or more local area networks.
It enables a group of devices available in multiple networks to be combined into one logical network.read more

Why VLANs are used:

  1. VLANs increase the number of broadcast domains while decreasing their size.
  2. VLANs reduce security risks by reducing the number of hosts that receive copies of frames that the switches flood.
  3. You can keep hosts that hold sensitive data on a separate VLAN to improve security.
  4. You can create more flexible network designs that group users by department instead of by physical location.
  5. Network changes are achieved with ease by just configuring a port into the appropriate VLAN.

What is VLAN trunking?

A network configuration that efficiently conveys data between multiple entities without using one-to-one links.read more

What is 802.1Q (DOT1Q) ?

The most widely used encapsulation method for VLAN tagging.

Spanning Tree

What is Spanning Tree Protocol (STP)?

A Layer 2 protocol that runs on bridges and switches.

What is the main purpose of STP:

Ensure that you do not create loops when you have redundant paths in your network.

You need to know:

Varieties of Spanning Tree Protocols What is BPDU What happens when disabling Spanning Tree

BPDU Guard

A feature is used to protect the Layer 2 Spanning Tree Protocol (STP) Topology from BPDU related attacks.

Want to know how to configure BPDU Guard in Cisco Switches?

Click Here

Cisco Discovery Protocol (CDP)

A Layer 2, media-independent, and network-independent protocol that runs on Cisco devices and enables networking
applications to learn about directly connected devices nearby.

This protocol facilitates the management of Cisco devices by discovering these devices, determining how they are configured, and allowing
systems using different network-layer protocols to learn about each other.

Want to know how to Use CDP?

Click Here

IP Routing

What is IP routing?

A process that sends packets from a host on one network to another host on a different remote network.

Read the next article to know how IP routing works

Advantages of IP Routing

  1. It offers stability
  2. It provides a robust network
  3. Offers dynamic routing update of the network paths
  4. Information is safe while transmitting

Dynamic Host Configuration Protocol (DHCP)

What is DHCP?

A client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other
related configuration information such as the subnet mask and default gateway.

Why use DHCP?

Every device on a TCP/IP-based network must have a unique unicast IP address to access the network and its resources.
Without DHCP, IP addresses for new computers or computers that are moved from one subnet to another must be configured manually.

Benefits of DHCP

  1. Reliable IP address configuration
  2. Reduced network administration

For more information about DHCP check this link.

Domain Name System (DNS)

DNS is what lets users connect to websites using domain names instead of IP addresses.

The DNS system is an open worldwide network of database name servers that include 13 authoritative name servers
that serve the DNS root zone level, known as "root servers".

Want to know how does DNS work?

Click Here

Variable Length Subnet Mask (VLSM)

VLSM is a subnet design strategy that allows all subnet masks to have variable sizes.

In VLSM subnetting, network administrators can divide an IP address space into subnets of different sizes, and
allocate it according to the individual need on a network.

Want to see the example of using VLSM?

Click Here

Network Time Protocol (NTP)

NTP is a protocol designed to time-synchronize a network of machines.

Want to know how it is working better? Watch video below:

Port Mirroring (SPAN)

SPAN (Switched Port Analyzer) is a dedicated port on a switch that takes a mirrored copy of network traffic
from within the switch to be sent to a destination.

The destination is typically a monitoring device, or other tools used for troubleshooting or traffic analysis.

SPAN ports present a readily available mechanism through which to access detailed packet information.

Want to know best practices of the Port Mirroring?

Click Here

Thanks.

I would be happy to hear your feedback 😄

P.S. And yeah, second part here