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Basics of Computer Networking and network devices

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Basics of Computer Networking and network devices

In this lesson of computer networking, we will discuss basic terms and definitions. This lesson is mainly designed for beginners who want to start their career in networking. So without wasting further time let’s get started.

What is a networking?

A group of together connected devices is called a network. Now if you are thinking why we need a network? Answer is very simple, to communicate with each other (share resources).

The process of interacting with each other to share information is known as networking.

Here, I am giving you an example for more clarity. All we are aware with the term social networking right. Social networking is a group of connected people. Similar way, computer networking is group of connected computer. I hope now it’s clear.

What is a host?

A host can be a computer, a laptop, a mobile, a internet printer or any other device that uses IP address to go to the internet.

What is a topology?

Topology simply defines how hosts are connected in a particular network.

There are many different topology- star topology, ring topology, bus topology, mesh topology and hybrid topology (mixture of all).

Define unicast, multicast and broadcast.

Unicast: Unicast means message is sent to only one host. In unicast mode there is one sender and one receiver.

Multicast: Multicast term is used when there is 1 sender and 2 or more than two receivers. Multicast is also known as one to many.

Broadcast: Broadcast means one to all. We use term broadcast when 1 sender sends information to all other hosts which are present in the network.

For example, in a network there are total 4 hosts, when frame will broadcast, it will send to all 4 hosts. In multicast, frame will send to more than 1 host (may be 2 or 3 hosts). In unicast, it will send to only 1 host.

What is Firewall?

Firewall is a network device that is used to secure our LAN network (trusted network) from outside untrusted networks. It could be software as well as a hardware device.

Firewall keeps an eye on the incoming and outgoing traffic and on the base of configured policies; it decides which traffic is allowed or which is denied. Firewall sits between switch and gateway.

Vendors: Paloalto, Checkpoint, Fortinet, Sophos

What is hub?

Hub is a LAN device. It works on layer 1 (physical layer). Hub is used in LAN network to connect host together. Now hubs are completely obsolete from the market.

There are two main reasons behind this, one is hub has less number of ports. As, the network size is increasing day by day, we need to connect more devices in a LAN, so we need a device that has large number of ports.

And the second is hubs are dummy device, simply broadcast the frame, more likely repeater.

What is bridge?

Bridge is a network hardware device that used to connect the hubs together.

What is Switch?

Switch is a layer 2 device (data link layer). Switch is the advanced version of hub, so sometime called as intelligent hub. Switch is used to connect hosts in the LAN network.

The basic function of a switch –to forward the frame. Switches maintain a ARP table that contains MAC address and port number.So, unlike hub switch doesn’t broadcast every time, it receives the frame then check the table and then forward the frame. Switch broadcast the frame only when ARP table is blank.

Now days, multi-switches are also available in the market. Multi-switch works on both layer 2 and layer 3. You can use multi-switch as a router as well as a layer 2 switch.

Vendors: Cisco, Juniper Networks, Huawei, HP, Dlink, tplink.

What is a Router?

Router is a layer 3 device (network layer). It is used to connect two different networks. The primary function of router is to forward the packets. Routers maintain a routing table that consist a list of best routes. So, whenever a packet comes, it first checks the routing table, then selects the best path and in last forwards the packet to next hop.

Vendors: Cisco, Juniper Networks, Huawei, Nokia.

What is Gateway?

Gateway is the entrance/exit point of a LAN network. Gateway is basically a router. Like in our home, there is a main gate through which we enter into home or go outside to the home. Similar way, gateway is that router through which outside traffic comes inside and inside traffic goes outside.

What is modem?

Modem stands for modulation and demodulation. Modem performs both modulations as well as demodulation depends on the requirement. At receiver side, it performs demodulation, convert analog signal (electrical signal) into binary form (10011011000011). At sender side, it performs modulation and converts digital signal into analog signal, just opposite of demodulation.

Modulation and demodulation are opposite to each other. Here, modulation convert digital signal into analog signal and demodulation convert analog signal into digital signal.

What is a repeater?

Repeater is a layer 1 device. Repeater is used to achieve the original strength of the signal. For example when we transmit a signal for a large distance, signal strength fades away as it travels more distance. So we use repeater at a fixed distance to recover the original signal strength.

Repeater name itself defines its function, repeat whatever it receives. The only thing that you need to remember it receives weaker signal and perform some amplification and then retransmits the signal with original signal strength.

What is Access point(AP)?

In traditional networks, our LAN network is wired one. I mean all devices are connected together through wired connection. But, now the scenario is different, LAN networks have both type of hosts wired host and wireless host. To connect wireless devices to wired network, we use access points.

In other words, we can say access points are used to merge wireless network into existing wired network to achieve proper utilisation of resources.

Sometimes APs are used to extend the signal range (works as range-extender).

WLC  are used to manage the Access points.

What is NIC?

NIC stands for Network Interface Card. It is a small circuit board (chip) on the motherboard of PC. NIC connects a computer to the internet. On NIC, there is a RJ-45 port. NIC has a MAC address (physical address) that is assigned by manufacturer.

Note: I remember in one of my interview, interviewer asked how we check NIC is working properly or not?

As we study NIC connects a computer to the internet. So, on the basis of that i simply answer I will check my internet connection if it is working properly, it means NIC is fine.

Now I tell you what interviewer said in the reply- he said if internet is not working, it doesn’t mean every time it’s because of NIC failure there may be some other reasons also.

So, now what is exact answer for “how we check NIC is working properly or not”.

To check whether NIC is working or not, we use loopback address 127.0.0.1.

It’s very simple process, go to the cmd(command prompt), then type ping 127.0.0.1.

If you get ping reply, it means NIC is working fine.  

Conclusion: In this lesson, we learned basics of networking and network devices. If you feel, I need to add some more basic things then let me know below in comment section.

What is IP Address? Explain in brief.

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What is IP Address? Explain in brief.

In this lesson, we will learn IP address concept in detail.

What is IP address?

An IP address stands for internet protocol address. IP address is a unique identity of a device.  It means it uniquely identifies a device on the internet. Every device requires an IP address to connect to internet. Without an IP address a device can’t access internet. So, this way you can understand the importance of IP address in computer networking.

IP address is a string of binary numbers in the form of 1 and 0.

Ex- 10101110 11110011 11111000 00101010

This is an example of 32 bit IPv4 address. Similar way in IPv6, we have 128 bits.

In above example we divided 32 bits into 4 pairs. Each pair consist 8 bits. (8bits = 1 octet).

So, in IPv4 we have 4 octets.

Decimal dotted representation of above IP – 174.243.248.42

Note: In binary number system we have only two bits 1 and 0. So, whenever you read data in binary format or something like that it means it is in the form of 1’s and 0’s.

2 Types of IP Address

IPv4 address (32 bits address)

IPv6 Address (128 bits address)

Note: Here v stands for version. So, we can expand like that IP version 4 and IP version 6.

How I can check IP address of my computer (for windows)?

1st method

  1. Go to the desktop, now type cmd in the window search bar and hit enter button.
  2. After that command prompt screen will be open.
  3. Look carefully, there will be a cursor blinking, now just type ipconfig.

2nd method

  1. Go to the desktop, now type “ncpa.cpl” in the window search bar and hit enter.
  2. Now a dialog box will appear on your screen to shows network connection.
  3. Click on the network from which you are connected, then a dialog box will appear.
  4. In this dialog box, there is a detail option, click on that.
  5. Now you able to see the IP address of your computer.

What are the classes of IPv4 Addresses?

IPv4 Addresses are divided into 5 Classes, These are divided by IANA :- Internet Assigned Number authority.

  1. Class A (1-126)
  2. Class B (128-191)
  3. Class C (192-223)
  4. Class D (224-240)
  5. Class E (241-239)

Class A, Class B and Class C IP address are used to assign IP to hosts (a host can be a router, switch, PC, mobile)

Class D IP address are used for multicasting purpose.

Class E IP address reserved for future use, but these address are not compatible with any device, so now they are wasted.

Now we will discuss some important parameters that are very important:

IPv4 address has 32 bits.

Ex- 10101110 11110011 11111000 00101010

For Class A-

  • First 8 bits are network bits and rest 24 bits are host bits.
  • Subnet mask for Class A: 255.0.0.0
  • Prefix length: 8 (prefix length represents the no. of network bits.)

For Class B-

  • First 16 bits represent network bits and remaining 16 bits represent host bit.
  • Subnet mask for class B: 255.255.0.0
  • Prefix length: 16

For Class C-

  • First 24 bits are network bits and remaining 8 bits are host bits.
  • Subnet Mask for class C: 255.255.255.0
  • Prefix length: 24

Class

Leading bits

 Network bits

Host bits

No. of Networks

Addresses per Network

A

0

8

24

128

16,777,216

B

10

16

16

16384

65,536

C

110

24

8

2,097,152

256

How to Calculate Subnet Mask?

It is a very easy process, once you will learn the method then you will calculate for any prefix length.

Replace all the network bits by 1 and all the host bits by 0.

Now we will do 1 problem to understand this in more clear way-

  1. 192.168.1.0/24 – (Class C address with prefix length 24. As I told you earlier prefix length represents network bits. So, here we have 24 network bits and 8 host bits.)
  2. First perform binary to decimal conversion.

192 .    168       . 1           .   0

11000000.10100000.00000001.00000000

  1. Now replace all network bits by 1 and all host bit by 0.

11111111.11111111.11111111.00000000

  1. Now again perform binary to decimal conversion and here we have

255.255.255.0

How we recognize the IP address class?

By looking at the first octet, you can recognize the class of an IP address.

For Class A: first binary octet is 0xxxxxxx. Here, you can see for Class A first bit of first octet is 0. Here x means it could be either 0 or 1.

In decimal notation, first octet always will be lies in the range of 1 – 126. And rest lie in the range of 0-255. First octet decimal range is 1 -126.

For Class B: first binary octet is 10xxxxxx. So, you can see for Class B first 2 bits of first octet always will be 10.

Decimal Octet range: 128-191

For Class C: First binary octet always will be 110xxxxx.

Decimal Octet range is 192-223.

For Class D: First binary octet always will be 1110xxxx.

For Class E: First binary octet always will be 1111xxxx.

Although, Class D and Class E address will not used in configuration.

What is Public IP?

Public IP is provided by Internet service provider (ISP). Public IP is globally unique. A host with private IP can’t go to the internet. So, whenever a host sitting in our LAN network, want to go on internet, first router performs NAT to convert private into public IP then it forwards the request to the internet.

What is Private IP?

Private IP is used in LAN network only. Sometimes, private IP also called LAN addresses. Private IP is uniquely defined in a LAN network. It means inside a LAN network, you can’t assign same IP address to 2 different hosts. Although, you can assign same IP address in 2 different LAN networks.

There are certain addresses in each class of IP address that are reserved for Private Networks.

Class A 10.0.0.0 to 10.255.255.255

Class B 172.16.0.0 to 172.31.255.255

Class C 192.168.0.0 to 192.168.255.255

What is static IP?

Static IP is not a type of IP, it’s kind of terminology. When an IP address is manually configured in a host then it is called as static IP. And the reason is manually configured IP will not change until you change it manually. We mostly configure IP address manually in routers and switches.

What is Dynamic IP?

When an IP address is configured through DHCP then it is called as dynamic IP. Mainly for LAN network we configure DHCP server. DHCP server automatically assigns the IP to the hosts.

What is APIPA address?

APIPA stands for Automatically Private IP Address Assignment. When DHCP server fails, automatically an IP address is generated and this address is called as APIPA address. APIPA assigns a class B address, range from 169.254.0.0 to 169.254.255.255.

Expected Interview questions from IP addressing concept are- (for freshers)

  1. What is a bit? ( I know this is very basic question, but I remember in one of my interview, interviewer asked this question.)

So, I answered bit is the smallest unit of data. In binary we have 2 bits that are 1 and 0.

  1. How many bits in IPv4 address?
  2. How many bits in IPv6 Address?
  3. How many classes in IPv4 Address? Define all classes with their address range.
  4. What are public IP and Private IP?
  5. What are static IP and Dynamic IP?

OSI MODEL IN CCNA

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What is OSI Model

What is OSI Model? Explain in brief.

OSI Model in CCNA

In this article, we will discuss OSI model and 7 different layers of OSI model CCNA. So, if you are curious or want to learn what is OSI model and how it works? Stay tuned with me till the end.

We will go step-by-step,

So, first we discuss what OSI model is?

OSI model stands for open system interconnection model. It is a conceptual model or we can say reference networking model that help us to understand how internet works? How host from different vendors communicate with each other.

How OSI model came into picture?

Before OSI model, back in 1970s and 1980s, different vendors had their own networking model, but the problem was if a company bought computers from different vendors then they had to manage different networks.

For example, if a company bought computer from 3 different vendors then they had to manage 3 different networks. And in the last one more network was required to merge all these networks.

So, this way you can see things were very difficult before the invention of OSI model and TCP model. To make things simpler, the international organization of standardization (ISO) took the task to create a model that is compatible with all vendors and that model is OSI model.

What is a network model?

A networking model is a set of protocols and standards that describes different functions in a layered structured. OSI model and TCP/IP model are two popular networking model.

OSI Reference Model in Networking?

The OSI reference model is a conceptual model that divides the functions of a communication system into seven layers. The OSI model provides a framework for the discussion, design, and implementation of data communication protocols.

It can be used as a blueprint for designing, implementing, and troubleshooting systems. The OSI Reference Model is also known as the OSI Model or TCP/IP Model.

What are 7 layers of OSI Model?

1. Application layer (layer 7)

2. Presentation Layer (layer 6)

3. Session Layer (layer 5)

4. Transport Layer (layer 4)

5. Network Layer (layer 3)

6. Data Link Layer (Layer 2)

7. Physical Layer (layer 1)

OSI layer protocols and functions-

1. Application Layer Function and protocols

Functions: End user (human) interacts with this layer.

Application software works on application layer. Application layer protocols provide services to the application software. For example application protocol HTTPs defines how web browsers pull the content from the web pages. Have you ever noticed most of URL starts with http or https? Here HTTP means hyper text transfer protocol that provides services to the web browsers to pull the content.

Other example, DNS (domain name system) that provides IP address to the corresponding domain when someone type a domain name in web browser.

In short, we can say application provides an interface between software running on a computer and the network itself.

Application layer doesn’t define the application software itself, it only provides the services that application software need.

Protocols: DNS, HTTP, HTTPs, SSL, Telnet

2. Presentation Layer Function and Protocols

Function: The primary function of this layer is to translate the data into appropriate form. For example data at application layer is in application format, it can’t be sent directly to the network. And similar way application can’t understand the data that come from below layers.  So, every time when data is sent or received presentation layer convert it into presentable form.

It encrypts or decrypts the data.

Here encrypt means when data come from application layer, it add some header to the data and then sent to the session layer. This process of encrypt the data is known as encryption.

Decrypt means when data come from session layer, it removes the header and after translation pass on the data to application layer. Decryption is just opposite the encryption process.

Protocols:  JPEG, MPEG, AVI

3. Session Layer Functions and Protocols

It controls the session between communicating hosts. It establishes the session, manages the session and finally terminates the session.

Key point:  Application developer work on these 3 top layers of OSI model to connect their application over network. Network engineers don’t work with these 3 layers.

4. Transport layer Functions and Protocols

Function: Transport layer is known as the heart of OSI model. It is responsible for end-to-end delivery (also called host-to-host communication).

It segments and reassembles the data. When data comes from upper layer, it breaks the data into small segments. And when data comes from lower layer it reassembles the segments into data and pass on the session layer.

Protocol: TCP and UDP

PDU(Protocol data unit): Segment

5. Network Layer Functions and Protocols:

Function: Network layer provides connectivity between end hosts.

Routers or multilayer switch (L3 switch) work on network layer. They manage a routing table that helps to select the best path. This way, we can say network layer provides best path between source and destination.

Network layer adds logical address (IP address).

Protocol: IP, ICMP, IPsec

PDU: Packet

Function: Data link layer provides node-to-node connectivity.

It detects and corrects the physical layer errors.

It adds 48 bit MAC address (also called physical address).

Switch, Bridge and NIC card work on layer 2.

Data link layer comprises of two sub-layers.

1) MAC (Media Access Control)

2) LLC (Logical Link Control)

Protocol: PPP and Ethernet

PDU: Frame

7. Physical Layer Functions and Protocols:

Function: It defines the physical characteristics of medium that is used to transmit the data like copper cable, fiber cable.

For example- voltage levels, current levels, maximum transmission distances and cable specification etc.

At this layer binary bit stream of data (10100011101010010111100) is converted into electrical signals or radio signals depend on the transmission medium.

If data is transmitted through wired connection then binary data is converted into electrical signals and for wireless transmission binary data is converted into radio formats.

Protocol: Ethernet and Wi-fi

PDU: bit

Top Networking Certifications

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Top Networking Certifications

Network Kings Certifications

The networking industry is not a monolithic place. There are a host of certifications and certifications-related events and publications produced by and for networking professionals.

Network Certifications

Cisco Certified Network Associate (CCNA) is the entry level certification for IT Professionals. Cisco Certified Internetwork Expert (CCIE) is the entry level for IT professionals that want to get into the industry. CCNA is a popular certification, because its job is to make sure that the network is operational and can be used.

Learn CCNA training from Network Kings.

AWS Certification.

The acronym AWS stands for “Amazon Web Services”, and this is the type of service that AWS provides. Amazon Web Services (AWS) is a cloud computing service provided by Amazon.com. It allows users to use software and storage that are running on Amazon’s computers to run applications on their own computers or devices.

Amazon Web Services are designed to make it easy for users to get the computing power they need to run their applications or websites, even if they don’t have the expertise to build and maintain the technology themselves.

Learn AWS Directly from Cloud Engineers.

Cybersecurity – CEH
As cyber security becomes larger and more important to man’s existence, companies need to know that they have a properly trained staff that can protect their Network and End Devices.

Companies should also ensure that they are on the forefront of all new technology with regards to training their staff in cyber security issues. Cyber security is a key issue to many companies and must be handled in a responsible manner.

CEH Certification is one of the certification which will help you to start your IT Journey in Cybersecurity.

Learn CEH From Cybersecurity Experts.

CCNP – BGP MPLS
The Cisco Certified Network Professional (CCNP) certification is the most valuable IT certification you can get and the one that professionals with no previous networking experience tend to pursue the most. The certification is not just for those who want to work as a network engineer or supervisor; it’s also accepted in a wide range of IT roles, such as sales, IT management, and network security.

Learn CCNP Enterprise from TAC Engineer.

Cisco router cli configuration

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Cisco router cli configuration

Introduction to Cisco Router CLI (Command-Line Interface)

Introduction to Cisco IOS CLI (Command-Line Interface)

Cisco router cli configuration is easy to perform with the help of  cisco basics CLI commands, or you can simple login your user dashboard then:

Router configuration !!

Router> User mode
enable
Router# This is Privelege mode

Router#configure terminal

Router(config)This is Global configuration mode

Router(config)#hostname Nwkings

Nwkings(config)#interface e0/0
Nwkings(config-if)#ip address 1.1.1.1 255.0.0.0
Nwkings(config-if)#no shutdown

Nwkings(config)#interface e0/1
Nwkings(config-if)#ip address 2.1.1.1 255.0.0.0
Nwkings(config-if)#no shutdown

Nwkings#write

Nwkings#show ip interface brief
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 1.1.1.1 YES manual up up
Ethernet0/1 2.1.1.1 YES manual up up

——————— EASY WAY ———————
enable
configure terminal
hostname NWkings
interface e0/0
ip address 1.1.1.1 255.0.0.0
no shutdown
interface e0/1
ip address 2.1.1.1 255.0.0.0
no shutdown
write

CCNA VS CCNP CERTIFICATION

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CCNP - Cisco Certified Network Professional.

CCNA & CCNP Certifications.

CCNA certification tests professionals on switching, routing fundamentals, Its associate-level certification, and CCNP is more advanced level certification and cover understanding of WAN and LANs.

Networking has become an important skill for both IT professionals and the business world at large. However, networking professionals often struggle to determine which certification is appropriate. In order to cope with this, we’re going to look at some of the best networking certifications out there.

Networking professionals can find a career doing a myriad of things, such as system administrators, server administrators, data center administrators, help desk technicians, and network engineers, among others. But what are the top networking certifications that are currently in demand?

CCNA – Cisco Certified Network Associate.

Cisco Certified Network Associate (CCNA) is the entry level certification for IT Professionals. CCNA is the entry level for IT professionals that want to get into the industry. CCNA is a popular certification, because its job is to make sure that the network is operational and can be used.

CCNP – Cisco Certified Network Professional.

The Cisco Certified Network Professional (CCNP) certification is the most valuable IT certification you can get and the one that professionals with no previous networking experience tend to pursue the most. The certification is not just for those who want to work as a network engineer or supervisor; it’s also accepted in a wide range of IT roles, such as sales, IT management, and network security.

OSI Model

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What is OSI Model?

What is OSI Model?

In the simple words OSI model helps in framework for implementation and creating networking device and describe how the network applications on different systems can communicate with the network media. Below are the step-by-step instructions with examples:

What is OSI Model?

Segments – Port number – http 80, https 443
Packet – Source Ip address | Destination Ip address
Frame – Source mac address | Destination Mac address

What is OSI Model?

The applications which help humans to interact with each other.

What is OSI Model?
What is OSI Model?

Presentation Layer.

This layer is responsible for the representation of data.

Image : Jpeg, png, img
audio : mp3, wav
video : mp4, avi

It is used to present data to the application layer (layer 7) in an accurate, well-defined and standardised format.

Encoding means converting data into 0 & 1.
Encrypt – Atul – slakfhjalskfjhsal;fj123
Compression – Reduce the size

Default Routing CCNA Lab.

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Default Routing CCNA Lab.

Default Routing CCNA Lab.

A default route is used mostly for internet connections.

where destination is unknown, By default the router will forward all  traffic to ISP.

A default route is the route that takes effect when no other route is available for an IP destination address.

A default route defines where packets will be sent if no specific route for the destination network is listed in the routing table.

APPLE
enable
conf t
hostname Apple
int fa0/0
ip add 192.168.1.1 255.255.255.0
no shutdown
int fa0/1
ip add 200.1.1.1 255.255.255.0
no shutdown
ip route 0.0.0.0 0.0.0.0 200.1.1.2

ISP
enable
conf t
hostname ISP
int fa0/0
ip add 9.1.1.1 255.0.0.0
no sh
int fa0/1
ip add 200.1.1.2 255.255.255.0
no sh
ip route 192.168.1.0 255.255.255.0 200.1.1.1

This static route we will not use in real world as already we have NAT on our routers. NAT convert private ip into public IP.

For advance: https://nwkings.com/courses/ccna/

What Is STP?

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What is STP?

What is STP: Spanning Tree Protocol

STP stands for spanning tree protocol. STP is used to reduce layer 2 loops. By default, STP is running in all manageable switches.

For a good network design and to ensure network availability, some extra links are added to the network (redundancy). If any active link fails then traffic shifts to these redundant links. It means these links are used for backup purpose. The process of adding extra links is known as network redundancy.

As we know everything has its pros and cons, same here, redundant links are good for backup purpose, but they also create layer 2 loops. To avoid these loops STP is used. STP allows the network design to use redundancy without causing other problems (loops).

STP prevents layer 2 loops by placing redundant ports in a blocking state. These extra links acts as a backup that can enter in a forwarding state if an active interface fails.

Interface in a forwarding state behave normally. They send and receive all normal traffic. While interface in blocking mode only send/receive BPDU messages (Bridge Protocol data units).

By selecting which ports are in forward mode and which are in blocking mode, STP creates a single path between each point. This way, STP prevents from layer 2 loops.

Why we need STP?

  1. To reduce broadcast storm.
  2. MAC table instability- As MAC table keep changing because frames with same source MAC arrives on different ports.
  3. Due to loops, multiple copies of the frame arrive at the destination.

How does a root bridge elect?

Switches use bridge-ID to select the root bridge. Bridge-ID consist two parameters one is bridge priority and another is MAC address. The switch which has lowest bridge-ID is selected as a root bridge. First priority field is compared, if there is a tie, then MAC address is compared.

How process starts?

  1. ALL STP-enabled switches sends Hello BPDU message to each other.
  2. Before sending BPDU message next time, switch compares it’s BID with received BID (inside BPDU message), when received BPDU has lower BID, it stops advertising itself.
  3. The same process repeats, and the switch which has lowest BID become root bridge.

People also search for:

What is STP protocol?

STP protocol is a protocol that is designed to make IP traffic management more efficient.

STP protocol was created by Cisco and it was first introduced in 1998. It is used for IP traffic management and it provides a way for network devices to communicate with each other about which paths are available, which ones are congested, and how to avoid congested paths. 

What is Spanning Tree Protocol and how does it work?

Spanning Tree Protocol is a networking protocol that provides a loop-free topology for any bridged LAN.

It is a protocol that guarantees a loop-free network topology for any bridged LAN by blocking redundant or unnecessary paths through the network. It does so by creating a spanning tree within the physical network.

What is difference between STP and RSTP?

STP stands for “Spanning Tree Protocol” and RSTP stands for “Rapid Spanning Tree Protocol”. STP is a standard that is used to prevent loops and stop broadcast storms on a network. It prevents the network from becoming congested by blocking redundant paths and selecting a single path to forward data.

RSTP is an enhancement of STP that allows it to recover more quickly after a link failure or when new devices are added to the network. This protocol has been designed with the intention of making it faster than STP.

What is difference between STP and RSTP?

The STP protocol is a new technology that aims to solve some of the problems with TCP.

It will fix some of the problems with TCP such as latency and packet loss.

This article will cover why we need STP, how it works, and what its advantages are.

Network Issues and Solutions

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5 Most Commonly Occurred Network Issues and Solutions

5 Most Commonly Occurred Network Issues and Solutions

In this article, I will share the 6 most commonly occurred network issues and their remediation method. To resolve any issue, the first thing is to understand the problem properly and try to find out what is the reason behind this problem and then start troubleshooting. This is applicable in real-life problems too and without understanding the root cause of the problem no one can solve it.  

1.Single PC (host) unable to connect to the internet:  

In a LAN network, if only a single workstation is not able to connect to the internet and all other hosts are working fine, then the issue must be related to that individual host only.  

Remediation: 

To resolve this kind of issue, first check the cable connection, network interface card and restart the PC. If there is no issue with the hardware part. Then we will move to network adapter configuration- default gateway IP, DNS server etc everything is correct or not.  Then check connectivity with the default gateway. If everything looks fine then check, if the appropriate port number is active or not. 

 

2. IP address exhaustion:

IP address exhaustion means all IPs are allocated, there is no free IP. To make sure that this is the IP address exhaustion problem, first, check IP address by using ipconfig command in CLI. If the host has an IP address that starts with 169.X.X.X (APIPA Address). This address is generated when a DHCP server fails. 

Remediation: 

This type of issue is common in cable internet connection, there is no local router and IP address is directly provided by the ISP on a limited basis. So, here is the solution: purchase a router or Wi-Fi access point with an integrated router, so that you can create your own pool of IP addresses according to the number of hosts and IP address exhaustion problem will not occur. 

If you already have a local router and after then you are facing an IP address exhaustion problem, then it may occur because your IP address pool range is smaller than the number of hosts in your network. In this situation, if you increase your IP address pool range, then this problem will be solved and will not occur again.  

2. Duplicate IP address:

This problem occurs when the DHCP server assigns an IP address that is already assigned to a network device. As we know, an IP address is a unique address, we can’t assign the same IP address to 2 different devices in the same network.  

Remediation: 

This type of problem occurs due to some silly mistake, so when you configure the DHCP server always make sure you exclude the IP addresses that are used by network devices. Generally, we configure static IP addresses for network devices like routers, servers and switches and we configure dynamic IP addresses (DHCP server) for other hosts in the network. So, at the time of DHCP pool configuration, leave the lower addresses for devices that require static IP (router, switch, server etc).  

 

4. DNS Problems: 

 The network path can’t be found, IP address could not be found, or DNS name doesn’t exist, if you see these messages on your screen then it will be a DNS configuration issue. 

Remediation: 

To fix this problem, change the DNS server configuration, allow the network devices to use their own server instead of DHCP assigned DNS server. Check the IPv4 setting of your adapter, if it shows a DNS server, then ignore this and select the DNS server address automatically. 

5. Slow Internet Performance: 

Slow internet speed problems mainly occurred due to 2 reasons, traffic congestion and bandwidth exhaustion, both are interrelated. Here traffic congestion means more users is more. 

Remediation:  

Use a speed test website to check your internet speed. This will help you to understand the reason why the internet is slow. It is due to some technical issue from the ISP end or because of traffic congestion. In the case of cable connection, the local network is shared with multiple users, so in that case, if your internet speed is slow and frequently the same problem occurs, then contact your ISP and tell them your issue and then he will provide you a high bandwidth connection.