How to Choose a Laptop for Students in India (2026 Guide)

How to Choose a Laptop for Students in India (2026 Guide)

Student using a laptop for online classes and study

Choosing the right laptop for students in India depends on three main factors: course requirements, budget, and everyday workload. A student who mainly attends online classes, prepares assignments, and browses the internet may not need the same hardware as a student who uses programming, engineering, graphic design, or video editing software.

Buying an expensive laptop does not automatically mean getting the best laptop for your studies. The right choice is a device that runs your required applications comfortably, offers sufficient storage and battery life, and fits your budget.

This guide explains how to choose a laptop for students by comparing processor performance, RAM, SSD storage, graphics, display quality, portability, and software compatibility. It also includes a comparison of real laptop configurations and practical advice for different student workloads.

Factors to Consider When Choosing a Student Laptop

Before purchasing a laptop, identify your study requirements and compare the features that affect your daily work. This can help you avoid paying for hardware you may not need.

1. Identify Your Study Requirements

Start by listing the applications and tasks you expect to use on your laptop.

  • School students: Online classes, documents, presentations, educational websites, and research.
  • College students: Assignments, presentations, research, video meetings, and course-specific software.
  • Computer science students: Code editors, development environments, databases, and programming tools.
  • Engineering students: CAD, simulations, technical drawing, and discipline-specific applications.
  • Graphic design students: Illustration, photo editing, typography, and design applications.
  • Video editing students: Video editing, media storage, rendering, and sometimes animation.

These categories are starting points, not strict rules. Two students in the same course may need different laptops because they use different software or work on projects of different complexity.

Practical tip: Check your college's recommended specifications and the official system requirements of your essential applications before buying a laptop.

2. Set a Realistic Budget

Your budget should reflect your study requirements rather than the popularity of a brand. Compare laptops within your budget and check their complete specifications.

Two laptops with similar prices may have different processors, memory capacities, displays, battery performance, and upgrade options. Consider additional expenses such as a laptop bag, accessories, warranty extensions, and necessary software subscriptions.

Do not choose a laptop based only on a processor label such as Core i5 or Core i7. The exact processor model, power limits, cooling system, and overall laptop design can affect performance.

3. Check RAM, Processor, and Storage


Laptop specifications including RAM SSD processor and graphics
  • RAM: Helps the system manage active applications and multitasking.
  • Processor (CPU): Executes instructions and calculations needed to run software.
  • Storage: Holds the operating system, applications, documents, and project files.

A laptop with sufficient RAM and a suitable processor can handle your workload more comfortably. An SSD can also help the system start up and open applications quickly.

Check whether RAM and storage can be upgraded later. Some laptops have soldered memory or limited upgrade options, so verify the specifications of the exact model before purchasing.

4. Compare Battery Life, Weight, and Display

Battery life matters for students who attend classes or study away from a power outlet. Advertised battery life may differ from actual results because of screen brightness, applications, network use, and other conditions.

A lightweight laptop can be convenient when travelling between home, college, and the library. Choose a screen size that balances portability with comfortable reading and working.

Also compare screen resolution, brightness, keyboard comfort, trackpad quality, weight, and display readability. For graphic design, illustration, and photo editing, colour accuracy may be particularly important.

5. Check the Keyboard, Webcam, and Connectivity

Students frequently type assignments, prepare presentations, attend online classes, and communicate with teachers. A comfortable keyboard can make long writing sessions easier, while a suitable webcam, microphone, and speakers are useful for video meetings.

Check whether the laptop has the ports you need for USB devices, headphones, external displays, and other accessories. Reliable Wi-Fi connectivity is also important for online learning and research.

6. Confirm Operating System and Software Compatibility

Before purchasing a laptop, verify that its operating system supports the applications required for your course. Some applications work across multiple operating systems, while others require a particular operating system or hardware configuration.

Students considering Windows, macOS, or ChromeOS should check compatibility with their college applications, examination software, programming tools, and other essential services.

For Windows laptops, consult Microsoft's official Windows 11 system requirements. Meeting minimum operating system requirements does not necessarily mean a laptop will perform well with demanding applications.

Real Laptop Specification Comparison for Students in India

Comparing actual laptop configurations can help students understand why processor, memory, display, and upgradeability matter. The following examples use specifications published on manufacturer websites. They are illustrative configurations, not a ranking of the best laptops available.

Acer Aspire 3 A311-45 laptop

Laptop modelProcessorRAM and storageDisplayImportant consideration
Acer Aspire 3 A311-45Intel Celeron N45008 GB RAM, 512 GB SSD11.6-inch HDCompact display; assess processor performance and screen size carefully.
Lenovo IdeaPad Slim 3, 82XQ01WDINAMD Ryzen 5 40 Processor, as listed by Lenovo8 GB soldered RAM, 512 GB SSD15.6-inch Full HD TNRAM is soldered; consider the display panel type and long-term memory needs.
HP Laptop 15-fd0465TU13th-generation Intel Core i38 GB RAM, 512 GB SSD15.6-inch Full HDIncludes a 1080p camera; verify the exact configuration and upgrade options.

Research note: Specifications are based on the linked manufacturer listings. Confirm that the exact model number and configuration match the product being sold. Availability and specifications may change.

Note: These images are for illustrative purposes only and may not represent the actual laptop models. Please visit the official manufacturers’ websites to verify the actual product images, specifications, and features.

What Does This Comparison Tell Students?

Storage capacity alone does not determine performance. These configurations list 512 GB of SSD storage, but their processors and displays differ. Students should compare the complete specification sheet rather than assuming laptops with similar storage offer similar performance.

Upgradeability matters. The listed Lenovo configuration has soldered RAM. Students should decide whether 8 GB will meet their future needs before purchasing it. Always check the exact model's memory configuration.

Display size and resolution are not the same as display quality. A larger Full HD display may be more comfortable for assignments and multitasking than a smaller HD display. However, resolution alone does not determine brightness, colour accuracy, viewing angles, or outdoor readability.

Do not choose a laptop from a specification table alone. Review the exact processor model, battery information, warranty, software compatibility, and current price before deciding.

How We Evaluated These Specifications

This is a specification-based comparison using information published by the manufacturers. It is not a physical performance test. No independent battery testing, benchmark measurements, or hands-on testing results are claimed.

Prices and availability may change. Check the official product pages before purchasing.

Which Type of Laptop Is Suitable for Students?

Budget and Everyday-Use Laptops

Students who mainly use a laptop for online classes, web browsing, documents, presentations, and streaming can consider an affordable model with suitable specifications.

For many basic student workloads, 8 GB of RAM and a 256 GB SSD can be reasonable starting points. However, these are not universal requirements. Students who keep many applications open or install larger software packages may benefit from additional memory or storage.

Before purchasing an entry-level laptop, check its processor performance, operating system support, display quality, keyboard, and upgrade options.

Laptops for Programming and Engineering

Programming students may need to run code editors, development environments, databases, or virtual machines. A suitable processor, sufficient RAM, and SSD storage can help these applications run efficiently.

Engineering requirements vary by discipline. Students who mainly write code may have different needs from those who run CAD applications, simulations, 3D modelling software, or other resource-intensive programs.

Some engineering applications benefit from dedicated graphics, while others rely more heavily on processor performance and system memory. Check your institution's recommendations and the software manufacturer's requirements before choosing a configuration. Intel's guide to laptops for engineering students provides additional background.

Laptops for Graphic Design and Video Editing

Creative work can require more processing power, memory, storage, and display quality than everyday academic tasks.

Graphic design and photo editing students should pay attention to display colour accuracy, RAM, and application compatibility. Video editing, animation, and 3D modelling can require more powerful hardware, depending on project resolution, file sizes, effects, and software.

Dedicated graphics may benefit some creative applications, but not every design student needs a powerful discrete GPU. Check the recommended specifications of your actual software before spending more.

2-in-1 Laptops for Note-Taking

A 2-in-1 laptop can function as a conventional laptop and, on compatible models, as a tablet. This can be useful for students who want to type assignments, annotate documents, write handwritten notes, or draw diagrams with a compatible touchscreen and stylus.

Before buying one, compare its weight, battery life, keyboard, stylus support, display, and price with those of a traditional laptop. A 2-in-1 model is worth considering if you will regularly use its tablet features.

What Laptop Specifications Do Students Need?

The following table provides general starting points. Actual requirements depend on software, workload, budget, and the laptop's overall performance.

Student workload RAM to consider SSD storage to consider Graphics
Online classes and assignments 8 GB can be a starting point 256 GB can be a starting point Integrated graphics are generally sufficient
Programming and general college work 8–16 GB, depending on tools 256–512 GB, depending on projects Integrated graphics are often sufficient
Graphic design and photo editing 16 GB may be useful 512 GB or more may be helpful Depends on the application
Video editing and 3D modelling 16 GB or more, depending on workload 512 GB or more, depending on project size Dedicated graphics may be beneficial

These figures are general guidance, not universal requirements. Check the official software requirements before making a purchase.

How Much RAM Is Suitable for a Student Laptop?

RAM stands for Random Access Memory. It is temporary, volatile memory that helps a laptop manage active applications and data.

For online classes, document editing, web browsing, and basic assignments, 8 GB of RAM can be a reasonable starting point. Students who regularly use programming tools, virtual machines, data analysis applications, graphic design software, or video editing programs may benefit from 16 GB of RAM or more.

The amount of RAM you need depends on the applications you use, how many run simultaneously, and the size of your projects. Also check whether the laptop's RAM can be upgraded.

How Much SSD Storage Do You Need?

An SSD (Solid-State Drive) is a storage device that holds the operating system, applications, documents, and project files. SSDs generally offer faster startup and application-loading times than traditional hard disk drives.

A 256 GB SSD may be sufficient for students who mainly work with documents, presentations, web browsers, and basic applications. Students working with large video files, datasets, design projects, or many software applications may benefit from 512 GB or 1 TB of storage.

Estimate the space your applications and files require before purchasing. External storage or cloud storage can help, but consider internet access, privacy, and backup requirements before relying on these options.

Integrated vs. Dedicated Graphics

Integrated graphics are built into the processor or system-on-chip. They are generally suitable for everyday tasks such as browsing, office applications, streaming, and basic photo editing.

Dedicated graphics use a separate graphics processing unit (GPU), usually with its own graphics memory. A dedicated GPU can improve performance in certain demanding tasks, including 3D rendering, advanced video editing, and some engineering applications.

Not every student needs dedicated graphics. Choose according to your software requirements, project complexity, and budget.

Which Processor Should Students Choose?

The processor, also called the CPU, executes instructions and calculations that help applications run. Different processors offer different levels of performance, power efficiency, and capabilities.

When comparing laptops, check the exact processor model rather than relying only on labels such as Core i5 or Core i7. Processor generation, model, power limits, cooling, and the laptop's overall design can affect performance.

For everyday academic tasks, a high-end processor may be unnecessary. Students running demanding applications should check the CPU requirements of their software.

How to Choose a Laptop Based on Your Course

Laptop use for college study programming and design work


School and College Students

School and college students often use laptops for research, online classes, presentations, assignments, and video meetings. A laptop with suitable everyday performance, adequate storage, a comfortable keyboard, and good portability may be sufficient.

Before buying, check the applications your school or college requires. If you expect to use specialised software later, consider its requirements when comparing models.

Computer Science Students

Computer science students may need to run code editors, development environments, databases, virtual machines, and data analysis tools. Sufficient RAM, a capable processor, and SSD storage can help with these tasks.

Students working with machine learning, large datasets, or resource-intensive development tools may need more powerful hardware. The right configuration depends on the programming languages, development tools, and applications required by the course.

Engineering Students

Engineering students should identify their discipline-specific requirements before choosing a laptop. A student who mainly writes code may need a different configuration from one who runs CAD, 3D modelling, or simulation software.

Check whether your course requires a specific operating system, dedicated graphics, a minimum amount of RAM, or particular processor capabilities. Confirm compatibility with the software versions used by your institution.

Design Students

Design students should consider the applications they use and the type of work they create. A good-quality display with suitable colour accuracy can be important for illustration, graphic design, and photo editing.

Video editing, animation, and 3D design may require more memory, storage, processor performance, or graphics capability. Check the recommended system specifications for your creative applications and estimate the size of your typical projects.

Common Mistakes to Avoid When Buying a Student Laptop

  • Choosing a laptop based only on its price or brand.
  • Ignoring the exact processor model.
  • Buying too little RAM for essential applications.
  • Underestimating storage requirements.
  • Assuming every student needs dedicated graphics.
  • Overlooking battery life, keyboard comfort, weight, and display quality.
  • Failing to check operating system and software compatibility.
  • Assuming RAM or storage can always be upgraded.
  • Ignoring warranty coverage, service availability, and return policies.
  • Paying for expensive features that are unnecessary for your coursework.

Before buying, compare the specifications with your study requirements and budget. This can help you make an informed choice and avoid unnecessary expenses.

Student Laptop Buying Checklist

student-laptop-buying-checklist

  • Confirm the applications required for your course.
  • Set a budget and compare suitable models.
  • Check the exact processor model and performance.
  • Confirm the amount of RAM and whether it is upgradeable.
  • Check SSD capacity and estimated storage needs.
  • Determine whether integrated or dedicated graphics are required.
  • Compare display quality, weight, and keyboard comfort.
  • Review advertised battery life and independent tests when available.
  • Check webcam quality, Wi-Fi, and required ports.
  • Confirm operating system and software compatibility.
  • Review warranty coverage, service availability, and return policies.
  • Compare the total cost, including necessary accessories and software.

Frequently Asked Questions

1. How much RAM is enough for a student laptop?

For basic online classes, assignments, and web browsing, 8 GB of RAM can be a reasonable starting point. Students who use programming tools, virtual machines, graphic design software, or video editing applications may benefit from 16 GB or more, depending on their workload.

2. Is an SSD important for a student laptop?

Yes. An SSD stores the operating system, applications, documents, and project files. It generally helps a laptop start up and load applications faster than a traditional HDD. Choose a capacity that suits your applications and file sizes.

3. Do students need a dedicated graphics card?

No. Integrated graphics are generally sufficient for everyday academic tasks. A dedicated GPU may benefit students who use demanding video editing, 3D modelling, rendering, or certain engineering applications.

4. Is a 256 GB SSD enough for college students?

It may be enough for students who mainly use documents, presentations, web browsers, and basic applications. Students working with large datasets, videos, design projects, or many software applications may need 512 GB or more.

5. Which processor is best for students?

There is no single processor that is best for every student. Compare the exact processor model and the requirements of your applications. Everyday academic tasks may not require a high-end CPU, while demanding technical or creative workloads may need more processing power.

6. Should students choose Windows or macOS?

The choice depends on budget, preferred applications, and course requirements. Check whether your essential software supports the operating system you intend to use. Students should also consider compatibility with college systems and specialised applications required for their course.

7. Is a 2-in-1 laptop worth buying for students?

A 2-in-1 laptop may be worthwhile if you regularly use handwritten notes, document annotation, drawing, or tablet mode. If you mainly type assignments and browse the internet, a conventional laptop may offer better value.

8. What should students check before buying a laptop?

Students should compare the processor, RAM, SSD storage, display, battery life, keyboard, connectivity, operating system, and software compatibility. They should also review upgrade options, warranty coverage, service availability, and return policies.

9. How can students compare laptop battery life?

Check the manufacturer's advertised battery life and look for independent tests of the exact laptop model when available. Actual results depend on brightness, applications, network activity, battery condition, and usage patterns.

10. Should students buy a laptop that can be upgraded?

Upgradeability can be useful if your needs change. Check whether RAM and storage are replaceable or soldered, and whether the manufacturer permits the upgrades you may need. Do not assume every laptop can be upgraded.

Conclusion

Choosing the best laptop for students in India depends on course requirements, budget, software compatibility, and daily workload. Students who mainly attend online classes and complete assignments may be comfortable with an affordable laptop that offers suitable everyday performance.

Programming and engineering students should compare processor performance, RAM, storage, and application requirements. Design and video editing students should also consider display quality and graphics capabilities.

Before making a purchase, compare exact specifications, review the software requirements of your course, and consider battery life, portability, upgrade options, warranty coverage, and total cost.

There is no single laptop that is best for every student. The right laptop is the one that meets your study requirements without making you pay for features you do not need.

References and Further Reading

  1. Google Search Central: Creating Helpful, Reliable, People-First Content
  2. Google Search Central: Guidance on Using Generative AI Content
  3. Google Search Central: Guide to Generative AI Features in Search
  4. Microsoft: Windows 11 System Requirements
  5. Intel: Tips for Choosing a Computer for School
  6. Intel: How to Choose a Laptop for Engineering Students
  7. Acer India: Aspire 3 A311-45 Specifications
  8. Lenovo India: IdeaPad Slim 3 Specifications
  9. HP India: Personal Laptop Listings

About the Author

Javed Iqbal Khan is the creator of the blog, a blog that shares information and practical guides on technology, search engine optimization (SEO), smartphones, and business.

The goal of this article is to help students understand laptop specifications and make informed purchasing decisions based on their academic needs and budget.

Research Methodology and Limitations

This article combines general technical guidance with specifications published on the linked manufacturer websites. The laptop comparison is specification-based and does not represent independent benchmark testing or hands-on product reviews.

Prices, availability, and configurations may change. Readers should verify the exact model number, current specifications, software compatibility, warranty terms, and price with the manufacturer or seller before purchasing.

AI-assisted tools may be used to help organise or edit content. Technical claims and recommendations should be reviewed against relevant sources before publication.

EIGRP Wide Metric Calculation

EIGRP Wide Metric Calculation
EIGRP Wide Metric Calculation

The EIGRP Metric has confounded many network experts who are trying to understand the protocol. The goal of this post is to define the Eigrp metric and show how to Eigrp wide metric calculation work.

EIGRP is a Cisco-developed routing protocol that dates back to the 1980s. As a result, Cisco was the sole vendor with the authority to implement the protocol. Until Cisco published the specification as an IETF draught in 1998. 

The ability to include many various factors while computing a route's cost, or metric, is one of EIGRP's key advantages. EIGRP is one of the few routing protocols that can calculate costs based on any combination of bandwidth, load, delay, and reliability.

What exactly are EIGRP Wide Metrics?


What exactly are EIGRP Wide Metrics

EIGRP calculates a composite cost metric based on bandwidth, latency, dependability, load, and K values. This metric has a flaw in that it does not scale for high-bandwidth links. 

In EIGRP topologies, the EIGRP Wide Metrics feature provides 64-bit metric calculations and RIB scaling. Only EIGRP-named mode setups provide 64-bit computations. 32-bit computations are used in EIGRP classic mode settings.

This topic explains how wide metric computation works quite well.

How does EIGRP calculate the metric?


Any routing protocol relies on metric calculation to function properly. The measure for a path is calculated by EIGRP using many criteria. By default, bandwidth and latency are used in metric calculations, but they can also include interface load and reliability. 

By default, EIGRP determines the optimum path to a remote network based on line bandwidth and delay. The ability to include many various factors while computing a route's cost, or metric, is one of EIGRP's key advantages.

EIGRP is one of the few routing protocols that can calculate costs based on any combination of bandwidth, load, delay, and reliability. The EIGRP metric calculation uses a delay value in tens of microseconds. Simply divide the DLY in the show interface command by 10 to get the Delay value.

Reported Distance

The metric describing the best route to access a network is known as the feasible distance (FD). In the routing table, that route will be shown. The metric given by an adjacent router for a particular route is known as reported distance (RD). In other words, it is the metric of the neighboring router's path to the network.

Bandwidth

In EIGRP, bandwidth is defined as the maximum amount of data that can be transmitted. To get the bandwidth value for the EIGRP metric, divide 10,000,000 by the bandwidth (in kbps) of the slowest link along the path to the destination network.
Delay is a cumulative measurement, unlike bandwidth, which denotes the "weakest link."

What is Delay in EIGRP

The overall delay in the path, measured in tens of microseconds (s), is called delay. The EIGRP formula is based on the IGRP metric formula, with the exception that the output is increased by 256 to make the metric 32 bits instead of 24 bits.

Reliability

A route's dependability metric is just a snapshot of the route's current reliability at the time it was last promoted. Remember that the EIGRP metric is retaken from the IGRP protocol, which was a timer-driven protocol. EIGRP, on the other hand, is an event-driven protocol.

EIGRP Load

Everyone studying EIGRP specifics is familiar with the "famous" composite metric formula, but the advice to keep the K values intact (or at least leave K2 and K5 at zero) or risk EIGRP's inability to adapt to changing load scenarios is rarely acknowledged.

IGRP, the forerunner to EIGRP, used the same vector metric and a very similar composite metric formula, but it was a real-time distance vector protocol (like RIP) that broadcast its routing information at regular intervals. It was fair to include interface load and dependability in the composite metric calculation because they were regularly conveyed throughout the network.

Formulas and K-Values

Each of these characteristics is controlled by a K-value. Each of these K-values allows one of the aforementioned attributes to be considered, as well as the scale on which the attribute is evaluated.

     K1 = Bandwidth  
     K2 = Load       
     K3 = Delay      
     K4 & K5 = Reliability

Each of these numbers is employed in a Composite Metric calculation devised by EIGRP.

EIGRP Metric:


256 * { K1*BW + [(K2*BW)/(256-load)] + (K3*delay) } * { K5/(reliability+K4) }

The K values are numbers ranging from 0 to 255. You can customize each value based on what you want to factor into the cost calculation for each route. 

You can set the relevant K-value to Zero in your routing domain if you don't want to examine one of the properties listed above. Set the relevant K-value to one if you want to consider an attribute.

You can scale how heavily a given number is regarded because the K-values can be any value between 0 and 255. 

Set the K1 value to 2, and the K3 value to 1, for example, if you want Bandwidth to be deemed twice as significant as Delay. Set K1 to 2 and K3 to 3 if you want to consider Bandwidth and Delay in a 2:3 ratio. 

This is why EIGRP's cost comparison is so flexible: you can choose which qualities to compare and how relevant each attribute is to your routing domain.

It should be emphasized, however, that two routers must have to match K-values before they may be EIGRP neighbors. This makes sense since if one router prioritizes Delay while the other prioritizes Bandwidth, they may argue about the optimum approach to a destination network.

Wide metrics use 64-bit values instead of 32-bit values. It works only in Named Mode not in Classic Mode because the K6 value is required in Wide metric calculation. K6 is used to measure Jitter, energy, or other future attributes. A simplified topology is shown here to show-

How does the Eigrp wide metric calculation work?

To check the K6 value, run the below command

#show ip protocols

Metric weight K1=1, K2=0, K3=1, K4=0, K5=0 K6=0

EIGRP Wide metric Formula:

Throughput = 65536 * 10^7 / minimum bandwidth across all links in the path

Latency =        65536 * total delay (in picoseconds) / 10^6

Composite metric = Throughput + Latency


Configuration for R1, R2 & R3

R1#conf t
R1(config)#interface f0/0
R1(config-if)#ip address 155.1.79.1 255.255.255.0
R1(config-if)#no shut
R1(config-if)#exit

Forming Neighborship:

R1#conf t
R1(config)#router eigrp MYKEY
R1(config-router)#ad
R1(config-router)#address-family ipv4 unicast autonomous-system 10
R1(config-router-af)#network 155.1.79.0 0.0.0.255
       
R1#sh ip eigrp topology 155.1.67.0/24

EIGRP-IPv4 VR(MYKEY) Topology Entry for AS(10)/ID(155.1.79.1) for 155.1.67.0/24
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is 19660800, RIB is 153600
  Descriptor Blocks:

  155.1.79.2 (FastEthernet0/0), from 155.1.79.2, Send flag is 0x0
      Composite metric is (19660800/13107200), route is Internal
      Vector metric:
        Minimum bandwidth is 100000 Kbit
        Total delay is 200000000 picoseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 1
        Originating router is 155.1.79.2

R2 Configuration

R2#conf t
R2(config)#interface f0/0
R2(config-if)#ip address 155.1.79.2 255.255.255.0
R2(config-if)#no shut
R2(config-if)#exit

R2(config)#interface f2/0
R2(config-if)#ip address 155.1.67.1 255.255.255.0
R2(config-if)#no shut 
R2(config-if)#exit

Forming Neighborship

R2(config)#router eigrp MYKEY
R2(config-router)#address-family ipv4 unicast autonomous-system 10
R2(config-router-af)#network 155.1.67.0 0.0.0.255

R3 Configuration

R3(config)#interface f0/0
R3(config-if)#ip address 155.1.67.2 255.255.255.0
R3(config-if)#no shut
R3(config-if)#exit

R3(config)#router eigrp MYKEY
R3(config-router)#address-family ipv4 unicast autonomous-system 10
R3(config-router-af)#network 155.1.67.0 0.0.0.255   

Wild Metric Calculation for the route 155.1.67.0/24 from R1

Throughput = 65536 * 10^7 / 100000 = 6553600

Latency =        65536 *200000000 / 10^6 = 13107200

Wild Metric = Throughput + Latency = 6553600+13107200 = 19660800

(minimum bandwidth across all links in the path=100000 kbps, Total delay=200000000 picoseconds)

FAQs: EIGRP Wide Metric Calculation

Q: How do I configure bandwidth in EIGRP?

Ans: We can use the IP bandwidth-percent Eigrp command to set this to a lower value to prevent EIGRP from flooding your interface(s). EIGRP traffic will then be queued and rate-limited by the router. On serial interfaces, Cisco router IOS will use a default bandwidth of 1544kbps.

Q: What exactly is K6 in EIGRP?

Ans: K6 was introduced with Wide Metric support and is used to enable Extended Attributes, which can be used to reflect a higher aggregate metric than those with lower energy usage. In the scope of this document, there are currently two Extended Attributes defined: jitter and energy.

Q: What exactly is an offset list in EIGRP?

Ans: An offset list is a mechanism for increasing incoming and outgoing metrics for routes discovered using EIGRP or the Routing Information Protocol (RIP). Only distance vector routing protocols use offset lists. An offset list can optionally be limited by specifying an access list or an interface.

Q: Is load balancing enabled by default in EIGRP?

Ans: EIGRP by default supports equal-cost load balancing across four links. Equal-cost means that multiple routes must share the same metric in order for the router to load balance across equal-cost links.

That's all.

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Networks Devices and Their Functions

Networks Devices and Their Functions

Networking-Devices


In the digital era, people around the world are connected just because of networking devices. These devices play a vital role in communication and provide an online platform for people to get in touch with other people across the globe. 

They can communicate through the internet, social media, and other modes of communication like cell phones, laptops, etc. It’s enough to mention It's all possible due to networking devices only.

The base of social media is the internet, even smartphones have networking equipment fitted to them. Some of the big networking companies have made it possible towards connecting people around the globe. Let's know some basic networks devices and their functions that are widely used in many organizations. 

Also read - What Is A Home Router?

What is Hub in Networking

Hub-in-networking

A hub is a networking device that is used to connect multiple Ethernet devices together. Hub has several ports that are used to connect two or more Ethernet devices together. It is a Layer 1 device and uses twisted-pair cabling to connect devices.  

Basically, a hub does nothing it just provides a path for the data signals. In addition, a hub does not perform any error checking and re-transmits any data packets or frames it receives on all its connected devices regardless of whether the data package is destined for the particular device. 

Hubs typically do not filter data that introduces congestion within the network.  Some important points should be mentioned here.

  • No routing and no MAC table available
  • 1 broadcast domain per device
  • 1 collision domain per device
  • HUB can not create VLAN
  • It is a Layer 1 (Physical Layer) Device

The Function of Bridge in Networking

In simple words, a bridge is a networking device that is used to connect multiple communication networks or network segments. It works at the Data link layer (Layer 2) of the OSI model. Ethernet bridge provides interconnection with other bridge networks that use the same protocol. Bridges forward data based on a MAC address (physical address). 

Bridges works at the Network Access Layer or data link layer in the TCP/IP model. In networking terms, a bridge filters and forwards packets based on physical address. Bridges are unable to read a specific IP address. It only works based on MAC addresses. Bridges are no longer used in modern LANs. 

Types of Bridges in Networking 

Generally, there are 3 types of bridges used in networking.

Source route type bridge is designed by the Tech giant IBM and used in token ring networks. The source route bridge determines the path between two host machines uses the frame's MAC destination address to direct it by the source routing algorithm. It learns its bridging information embedded within the frame.

Transparent bridges its name suggest the devices on the network are uninformed of its presence.  It does nothing except forward or blocking data packets based on physical address. It connects network segments with other bridges using similar media to make all routing decisions. All operations are transparent to devices connected to the network.

A transnational bridge in networking can be used to connect two different networks like Ethernet to Token Ring. It forward frames between LANs that utilize different network protocols. 

When a host wants to communicate with another host in a different network like a token to an Ethernet network, it transmits the frame (token ring frame) that the bridge receives, and rebuilds in Ethernet format. The bridge then transmits the frame to the destination host.

  • No routing but the MAC table is available
  • 1 broadcast domain per device
  • 1 collision domain per port
  • The bridge can not create Vlan
  • It is a Layer 2 (Data Link Layer) Device
  • Bridges are more expensive than the repeaters and hubs.

Switch In Networking

Switches-in-networking

Switches form the backbone of any network. The switch is an intelligent device and is widely used in modern networks. Ethernet switches or LAN switches are used to interconnect multiple networking devices together such as computers, printers, and wireless access points, and allow for exchanging data packets. 

A switch provides wired connections to routers, servers, desktop computers, printers wireless access points, and some IoT devices. A switch operates on both the data link layer (layer 2) and network layer (layer 3) of the OSI model. Layer 2 switch determines the path by looking at the physical device address (or MAC address) while the network switch performs based on the IP routing table and provides the shortest path for the destination host. 

Switches maintain their own MAC  tables. The switch has multiple ports for plugging in network cables. There are 4-port, 8-port, 16-port 32-ports, 48 ports, and 52 ports switches available in the market. 

  • No routing but the MAC table is available
  • 1 broadcast domain per device
  • 1 collision domain per port
  • The switch can create VLAN
  • It is a Layer 2 (Data Link Layer) Device


What is a Router and how does it work


We are all relying on a router for an Internet connection. Routers are responsible for maintaining data flow between different networks and for keeping internal networks connected to the Internet. 

A router is a Layer 3 device that is used to connect two different network segments and provide communication between them. Each router maintains its own routing table and determines the best path. it routes the data packets to their intended IP addresses. 

The router reads a packet's header to determine the destination address, then checks the routing table and provides the best path to that destination. It allows multiple devices to connect to the Internet simultaneously. Router exchange data between LAN and WAN. Generally, routers are operated at the gateways of networks.

  • Maintain Routing table and manage traffic
  • ARP table uses the IP address to determine the physical (MAC) address of the gateway.
  • 1 broadcast domain per port
  • 1 collision domain per port
  • L3 Device (Network Layer)


Different types of Routers

According to the application category, there are five major types of routers on the market. Wired routers, wireless routers, core routers, edge routers, and VPN routers are all types of routers. When deciding on a router, the following basic information is provided to assist you in making the best decision.

Wired Routers 

Older routers that receive and deliver data packets via both ends of a cable connection are known as wired routers. A wired router connects to a PC through a cable. One port receives Internet packets via modem, while the other connects to a computer and distributes the processed packets. The Ethernet broadband router is one of the most used wired routers. 

Typically, wired routers are made box-shaped, and use an Ethernet cable to connect to a modem for receiving Internet data packets. There are many ports in the router. One port allows the router to connect to a modem while another set of ports allows connecting the other devices for distributing data packets within the network. 

Such routers support the network address translation (NAT) method to connect internal devices to the WAN. It uses  Dynamic Host Configuration Protocol (DHCP) to assign an IP address to the devices connected to the networks. 

Wireless routers are more advanced because they use radio waves to deliver data to computers and other electrical devices. 

Wireless Routers 

Like a wired router, a wireless router uses an Ethernet cable to connect directly to a modem for receiving data packets. However, instead of using another set of cables for distributing Internet data packets, uses one or more wireless antennas. 

A wireless router is distinguished from a wired router. It is common in offices, homes, and other public places. Wireless routers, like wired routers, receive data packets over wired broadband, convert the binary-code packets into radio signals picked up by electronic devices, and then convert them back into previous packets. 

Wireless signals, as opposed to wired routers, are the medium through which packets are sent to electronic devices. The routers convert the data packets into radio signals, which the antennas broadcast wirelessly. Unlike wired connection, the wireless router establishes wireless LAN (WLAN) which is known as WiFi. So, as long as your device is within range of the signal, all you need to do to access the Internet is enter a specific ID and password. 

The WiFi network, with which we are all too familiar, is the most widely used wireless router. There is no limit to the number of users who can connect to the network with passwords, assuming your router is strong enough. Wireless routers are popular in the market due to their ease of use and high load capacity. To protect a wireless network, wireless routers provide MAC address filtering and (WPA) security.

Virtual Routers 

Unlike a wired or wireless router, a virtual router is a software application that uses Virtual Router Redundancy Protocol (VRRP) and performs the same function as a standard hardware router. It becomes active when a physical router fails or is disabled for some reason. A VPN router is similar to a standard Gigabit router that has VPN client software installed on it. VPN protects every device that connects to the VPN router. VPN routers, whether in your home, office or business, can provide a variety of VPN benefits to all devices.

Edge Routers 

In simple words, an edge router communicates with both external routers and core routers. Edge routers operate at the edge of a network and use the Border Gateway Protocol - BGP to exchange data from other networks.  Edge routers sit at network intersections, distributing packets across various networks and allowing several networks to speak with one another. The core router, on the other hand, is connected to the same network and handles huge data transfers quickly.

As the name implies, an edge router is located at the network's edge or boundary and distributes packets across multiple networks, but not within the same network. It is typically linked to the network of an Internet service provider (ISP) or another organization. Their job is to keep your network connected to other networks smoothly, and they can be wired or wireless routers. The edge router can communicate with the core router as well.

Core Routers 

Unlike the routers used within SOHO networks, Core routers operate at the core of a network and it is used by large corporations and businesses that manage a high volume of data packets within their network. Core routers do not communicate with external networks.  In contrast to edge routers, core routers distribute packets within the same network rather than across multiple networks. It is in charge of large data transfers and operates on the Internet's backbone. It is capable of achieving high-speed communication interface transmission for a wide range of communication interfaces, allowing all IP packets to move at full speed. 

Because core routers can connect distributed routers from multiple large enterprises or community locations in some cases, high performance is a must.

Wrapping up the article

I hope you are now familiar with the different Networks Devices available in the market. It will help you when choosing the correct network device through this analysis of the characteristics and pertinent information.



Dynamic Multipoint-VPN - Definition and Practical Guide

Dynamic Multipoint-VPN - Definition and Practical Guide
DM-VPN


Cisco DMVPN can be used to encrypt traffic between the organization and numerous partner sites, guaranteeing network segmentation by preventing spoke-to-spoke transmission even through the hub.

What is Dynamic Multipoint - VPN?


DMVPN or Dynamic Multipoint VPN is a Cisco solution that provides site-to-site VPN tunnels over the public WAN. It allows two different branch locations to communicate with each other over a secure tunnel. DMVPN provides scalable VPNs that are easy to implement and manage.

DMVPN works in combination with generic routing encapsulation (GRE) for tunneling, IPsec to provide a secure overlay network, and Next Hop Resolution Protocol (NHRP).

As we know multipoint GRE over IPsec works fine for fewer sites however the number of VPN gateways increases the more challenges and configurations will be required.

We'll go through each component's purpose and function in-depth, assuming the reader has a general concept of what DMVPN is and a solid knowledge of IPsec/CEF. In this post, we'll go over three stages of DMVPN evolution.

1) Hub and Spoke Phase 1 (mGRE hub, p2p GRE spokes)
2) Hub and Spoke with Spoke-to-Spoke tunnels (Phase 2) (mGRE everywhere)

A separate post will be necessary to cover DMVPN Phase 3. This is due to major modifications to NHRP resolution logic (NHRP redirects and shortcuts), which are better shown when the prior two stages are well understood. However, there will be some hints concerning Phase 3 in this post.

GRE Multipoint


Let's start with the most fundamental DMVPN construction block: the multipoint GRE tunnel. GRE tunnels are typically point-to-point, however, mGRE expands on this concept by allowing tunnels to have many destinations.

This may appear reasonable if the tunnel destination address is multicast. The tunnel might be used to successfully transport the same information (for example, a video stream) to various locations on top of a multicast-enabled network. 

In fact, Cisco IOS uses mGRE for Multicast VPN implementation in this way. If tunnel endpoints need to exchange unicast packets, a specific glue is needed to map tunnel IP addresses to endpoint routers' physical or real IP addresses. As we'll see later, this adhesive is known as NHRP.

It's worth noting that if you source multiple mGRE tunnels from the same interface (for example, Loopback0) of a single router, GRE can use a special "multiplexor" field in the tunnel header to distinguish them. 

This is known as the "tunnel key," and it can be defined under tunnel configuration. In fact, until IOS 12.3(14)T or 12.3(11)T3, the use of a "tunnel key" was required – the mGRE tunnel would not start until the key was configured. You can configure a tunnel without the key since the aforementioned versions.


Next Hop Resolution Protocol (NHRP)


Now, let's get to the part of DMVPN that truly makes it dynamic - NHRP. RFC 2332 defined the protocol quite some time ago to create a routing optimization scheme within NBMA (non-broadcast multiple access) networks such as ATM, Frame-Relay, and SMDS. The general idea was to use SVC (switched virtual circuits) to create temporary shortcuts in the NBMA cloud that were not fully meshed. NHRP performs a similar function to ARP in that it resolves L3 to L2 addresses, but it does so in a more efficient manner, making it suitable for partially meshed NBMA clouds that support dynamic layer 2 connections.

Next Hop Resolution Protocol (NHRP) Phase 1


NHRP Phase 1 is used by mGRE to notify the hub of dynamically appearing spokes. Initially, you configure each spoke with the hub's IP address as the NHS server. The spoke's tunnel mode, on the other hand, is a GRE (regular point-to-point) tunnel with a fixed destination IP that equals the physical address of the hub. 

The spokes can only connect to the hub and other spoke networks across the hub. The advantage of Phase 1 is that it simplifies hub router configuration by eliminating the need for static NHRP mapping for each new spoke.

Because all packets pass through the hub, almost any dynamic routing protocol would aid in achieving reachability. The hub only needs to advertise a default route to the spokes, while the spokes should dynamically advertise their subnets to the hub. 

It's probably a good idea to run EIGRP on the hub and summarise all subnets to 0.0.0.0/0, effectively sending a default route to all spokes (if the spokes do not use any other default route, e.g. from their ISPs). Configure spokes as EIGRP stubs and advertise the networks to which they are connected. RIP could be configured in a similar way by simply configuring GRE tunnels on spokes as passive interfaces.

Split-horizon must be disabled on the hub mGRE interface for EIGRP and RIP to exchange subnets from spoke to spoke. The point-to-multipoint network type should be used on all GRE and mGRE interfaces in OSPF. Configure the hub to use IP OSPF database filter-all out, as well as static default routes via spoke tunnel interfaces or static specific routes for corporate networks.

DMVPN Configuration - Phase 1, 2, 3


A DMVPN is powered by VPN routers and firewall concentrators. The spokes do not use a permanent VPN connection; instead, they communicate via a centralized hub-and-spoke model that can implement VPN protection and granular access controls as needed. DMVPN also supports IPsec encryption.

DMVPN is a point-to-multipoint Layer 3 overlay VPN that allows direct spoke-to-spoke communications, depending on the DMVPN design (Phase 1, Phase 2, or Phase 3).

Integrating IPsec with DMVPN


Isn't there something we've forgotten about DMVPN Phase 1/Phase 2? That is IPsec, one of the components that ensure the confidentiality and integrity of mGRE/NHRP. In comparison to the complexity of NHRP operations, IPsec integration is now simple.

First, the hub must understand how to use IKE to authenticate all of the spokes. The most scalable method is to use X.509 certificates and PKI, but for the sake of simplicity, we will simply use the same pre-shared key across all routers. 

To accept IKE negotiation requests from any other dynamic peer, we must configure the routers with a wild-card pre-shared key.

Because the hub has no idea what the IP addresses of the connecting peers are, we need dynamic crypto maps in IPsec Phase 2. Fortunately, Cisco IOS includes a cute feature called IPsec profiles, which is intended for use with tunnel interfaces. The profile connects to a tunnel interface and automatically considers all traffic leaving the tunnel to be IPsec Phase 2 traffic. 

The IPsec profile's IPsec phase proxy identities are the tunnel's source and destination host IP addresses. Because mGRE already provides tunnel encapsulation, it makes sense to use IPSec transport mode with it. Furthermore, IOS only supports some features, such as NAT traversal with IPSec transport mode.

Configuration -

In this configuration, I have used 7200 series routers. So let's begin configuration. I have made this diagram using GNS3. Before configuring dmvpn, all routers should interact with one another. IP OSPF 1 area o is used in this configuration. 




dmvpn


Router 5-

interface FastEthernet0/0
 ip address 172.16.1.4 255.255.255.0
 ip ospf 1 area 0

interface FastEthernet2/0
 ip address 172.16.31.4 255.255.255.0
 ip ospf 1 area 0
     
interface FastEthernet3/0
 ip address 172.16.41.4 255.255.255.0
 ip ospf 1 area 0
 


Hub Configuration (R4):-

HUB#sh ip int br
Interface                   IP-Address      OK? Method Status                Protocol
FastEthernet0/0        10.7.7.7          YES NVRAM  up                      up      
FastEthernet2/0        172.16.1.7      YES NVRAM  up                    up      

HUB#conf t
HUB(config)#interface f2/0
HUB(config-if)#ip ospf 1 area 0
HUB(config-if)#exit

Tunnel Configuration

HUB#conf t
HUB(config)#interface tunnel 100
HUB(config-if)#ip address 192.168.1.1 255.255.255.0
HUB(config-if)#no ip redirects 
HUB(config-if)#no ip split-horizon eigrp 1
HUB(config-if)#ip nhrp authentication cisco
HUB(config-if)#ip nhrp network-id 1
HUB(config-if)#ip nhrp map  multicast dynamic 
HUB(config-if)#tunnel source f2/0
HUB(config-if)#tunnel mode gre multipoint 

HUB(config-if)#router eigrp 1
HUB(config-router)#network 10.7.7.7 0.0.0.0
HUB(config-router)#network 192.168.1.0 0.0.0.255 

HUB(config-router)#do show ip nhrp

192.168.1.2/32 via 192.168.1.2
   Tunnel100 created 00:00:50, expire 01:59:10
   Type: dynamic, Flags: unique registered used 
   NBMA address: 172.16.31.6 

HUB#trace 10.5.5.5

Type escape sequence to abort.
Tracing the route to 10.5.5.5
VRF info: (vrf in name/id, vrf out name/id)
  1 192.168.1.3 368 msec 472 msec 500 msec

HUB#sh dmvpn 
Legend: Attrb --> S - Static, D - Dynamic, I - Incomplete
        N - NATed, L - Local, X - No Socket
        # Ent --> Number of NHRP entries with same NBMA peer
        NHS Status: E --> Expecting Replies, R --> Responding, W --> Waiting
        UpDn Time --> Up or Down Time for a Tunnel
==========================================================================
Interface: Tunnel100, IPv4 NHRP Details 
Type:Hub, NHRP Peers:2, 

 # Ent  Peer NBMA Addr Peer Tunnel Add State  UpDn Tm Attrb
 ----- --------------- --------------- ----- -------- -----
     1 172.16.31.6         192.168.1.2    UP 00:14:25     D
     1 172.16.41.5         192.168.1.3    UP 00:03:33     D


SPOKE1-

interface FastEthernet0/0
 ip address 10.6.6.6 255.255.255.0
!         
interface FastEthernet2/0
 ip address 172.16.31.6 255.255.255.0
 ip ospf 1 area 0

  interface Tunnel100

 ip address 192.168.1.2 255.255.255.0
 ip nhrp authentication cisco
 ip nhrp map multicast 172.16.1.7
 ip nhrp map 192.168.1.1 172.16.1.7
 ip nhrp network-id 1
 ip nhrp nhs 192.168.1.1
 tunnel source FastEthernet2/0
 tunnel destination 172.16.1.7

 router eigrp 1
 network 10.6.6.6 0.0.0.0
 network 192.168.1.0

SPOKE2-

interface FastEthernet2/0
 ip address 172.16.41.5 255.255.255.0
 ip ospf 1 area 0
!         
interface FastEthernet3/0
 ip address 10.5.5.5 255.255.255.0

interface Tunnel100
 ip address 192.168.1.3 255.255.255.0
 ip nhrp authentication cisco
 ip nhrp map multicast 172.16.1.7
 ip nhrp map 192.168.1.1 172.16.1.7
 ip nhrp network-id 1
 ip nhrp nhs 192.168.1.1
 tunnel source FastEthernet2/0
 tunnel destination 172.16.1.7

 router eigrp 1
 network 10.5.5.5 0.0.0.0
 network 192.168.1.0

Useful commands;-
show dmvpn
show dmvpn detail
show ip nhrp
show ip nhrp brief

---------------------------------------------Phase 3-----------------------------------------------------------

Tunnel Configuration

HUB#sh ip int br
Interface                   IP-Address      OK? Method Status                Protocol
FastEthernet0/0        10.7.7.7          YES NVRAM  up                      up      
FastEthernet2/0        172.16.1.7      YES NVRAM  up                    up      

HUB#conf t
HUB(config)#interface f2/0
HUB(config-if)#ip ospf 1 area 0
HUB(config-if)#exit

HUB#conf t
HUB(config)#interface tunnel 100
HUB(config-if)#ip address 192.168.1.1 255.255.255.0
HUB(config-if)#ip nhrp redirect
HUB(config-if)#no ip split-horizon eigrp 1
HUB(config-if)#ip nhrp authentication cisco
HUB(config-if)#ip nhrp network-id 1
HUB(config-if)#ip nhrp map  multicast dynamic 
HUB(config-if)#tunnel source f2/0
HUB(config-if)#tunnel mode gre multipoint 

HUB(config-if)#router eigrp 1
HUB(config-router)#network 10.7.7.7 0.0.0.0
HUB(config-router)#network 192.168.1.0 0.0.0.255 


SPOKE1-

interface FastEthernet0/0
 ip address 10.6.6.6 255.255.255.0
!         
interface FastEthernet2/0
 ip address 172.16.31.6 255.255.255.0
 ip ospf 1 area 0

  interface Tunnel100

 ip address 192.168.1.2 255.255.255.0
 ip nhrp authentication cisco
 ip nhrp map multicast 172.16.1.7
 ip nhrp map 192.168.1.1 172.16.1.7
 ip nhrp network-id 1
ip nhrp shortcut
 ip nhrp nhs 192.168.1.1
 tunnel source FastEthernet2/0
 tunnel destination 172.16.1.7

 router eigrp 1
 network 10.6.6.6 0.0.0.0
 network 192.168.1.0

SPOKE2-

interface FastEthernet2/0
 ip address 172.16.41.5 255.255.255.0
 ip ospf 1 area 0
!         
interface FastEthernet3/0
 ip address 10.5.5.5 255.255.255.0

interface Tunnel100
 ip address 192.168.1.3 255.255.255.0
 ip nhrp authentication cisco
 ip nhrp map multicast 172.16.1.7
 ip nhrp map 192.168.1.1 172.16.1.7
 ip nhrp network-id 1
ip nhrp shortcut
 ip nhrp nhs 192.168.1.1
 tunnel source FastEthernet2/0
 tunnel destination 172.16.1.7

 router eigrp 1
 network 10.5.5.5 0.0.0.0
 network 192.168.1.0

FAQs: Dynamic Multipoint-VPN

Q: What is the distinction between SSL VPN and remote access VPN?

Ans: An IPsec VPN allows connections between an authorized remote host and any system inside the enterprise perimeter, whereas an SSL VPN allows connections only between approved remote hosts and particular services available within the enterprise perimeter.

Q: SSL or VPN, which is more secure?

Ans: When a user logs into the network, SSL takes the lead in terms of security. SSL VPNs operate by gaining access to certain apps, but IPsec users are treated as full network members. As a result, SSL makes it easy to restrict user access.

Q: Is DMVPN only available from Cisco?

Ans: This is a Cisco-only protocol. You may simply scale your company network using the Dynamic Multipoint Virtual Point Network functionality. DMVPN with IPSec is used by even tiny businesses.

In this post "Dynamic Multipoint-VPN - Definition and Practical Guide", if you have any queries or suggestions please feel free to write. Thank You.