The Developing Minds

6 Life Lessons From The Himalayan Trek

2022-02-13T16:44:00.006-05:00

Far from the busy world, where there is zero signal, where the word 'busy' has no existence, that is where I've gathered these invaluable life lessons from a wonderful experience.

The story began with a single thought - Why don't I start my new year with an adventurous trek?

Kedarkantha trekking is considered one of the most visited and beginner-friendly winter treks.

This blog is intended on the life lessons that I've learnt from my trekking experience. Before that, why should you even bother to study further? Maybe one of the good reasons is to expand your perspectives.

Let's start.

Lesson 1
Expect The Unexpected.

We never thought that we can't reach the Kedarkantha peak because of heavy snowfall, this is completely unexpected. But then, it is just a travel scenario.
Similarly, we frequently come across so many unexpected situations in our lives. Sometimes, the intensity of the situations will be in a way that it questions your existence.

What I intend to say here is that unexpected situations may come in your life, but the response to those situations and how you handle such kinds of situations will be completely based on your mental strength. Always be strong emotionally and mentally.
Lesson 2
Never Give Up.

I can't even explain how many times I've heard this quote since my childhood. I've read it in many books, suggested by my parents and well-wishers a countless number of times.
For the first time in my life, I practically realized how important it is to never give up.

There are at least 10-12 instances where I literally wanted to go back even before reaching Juda-Ka-Talab. I have no patience at all to make one step ahead, full of irritation that why am I even here. But then something has happened which shook my perspective.

I looked around, everyone's still struggling but the only difference is that they're enjoying the journey even while they're struggling. People who are aged double than my age are jubilantly making one step at a time on the steep ascent. This completely changed my perspective for a moment, which made me push ahead and eventually reach Juda-Ka-Talab and see one of the world's beautiful sceneries.
Lesson 3
Focus on the step you're gonna take, that's it.

You don't have to focus on the whole staircase at once, just focus on the step that you're gonna take. The ascent was so steep when we started our trekking. During this process, one thing that I've clearly understood is - If you don't take care of the step that you're gonna take, who knows, you may not even reach the desired destination.

For example, let's say that I am looking at the top of the mountain, which is my goal, and taking the step. I am not aware of what's behind me, beside me, in front of me. What would eventually happen in this case?
I may fall down, my leg may get fractured and may not even reach the top of the mountain because of the severity of the situation.

To sum up, once you decide your goal, your utmost focus should not be on the goal, your utmost focus should be on the step that you're gonna take which makes you move closer towards your goal.
Lesson 4
Learn from others, be it positive or negative.

A wise person always learns from others. If it is positive, inspire from them and strive to include that in your lifestyle. If it is negative, learn and reaffirm that you shouldn't be that way and be careful.
In either of the cases, the common point is to learn from others, however tiny it can be, irrespective of the age factor.

In this journey, my brother-in-law inspired me in many ways. Some of them are - spontaneity in handling the situations sensibly, showing concern and helping others when they're in trouble as per one's capacity.
Lesson 5
Just pause and enjoy for a moment, life's already moving.

With increasing age, our responsibilities increase. With increasing responsibilities, our day-to-day pressures increase. But don't forget to take a pause and enjoy for a moment however stressful your day is. Cheer yourself up, try to do the same things differently. Most importantly, smile for a moment in a day.

What made me realize this is - during this journey, though our major focus is to reach Juda-Ka-Talab, we didn't let that from stopping our enjoyment. We laughed, we took pictures, we relaxed and we finally reached the destination.

To sum up, don't let the pressure in your life stop you from enjoying the life that you already have.
Lesson 6
Always be grateful, no matter what.

The life that you're living right now is someone else's dream. The clothes that you wear casually are someone else's dream clothes. The mobile that you use is someone's dream in a lifetime.
Appreciate and recognize the value of your life and be grateful to your life, no matter how worst you think your life is.

When we got to know that we can't go ahead in the journey because of heavy snowfall, we obviously were a bit saddened, but more than that we're all happy that we've reached at least till this point despite heavy snowfall and survived successfully for 2 complete days. I'm so grateful for all the experiences that I had during this trek.

These may not be the different things from what you've heard before. The only difference is that you've heard the same things from a different perspective, which is from my experience.

So I hope you've found this blog post useful and if you found this useful even to the slightest extent, I request you to share this with as many people as possible. After all, sharing is caring, isn't it?

As a side note, I've captured my trekking experience by shooting a vlog. If you're excited, you can check it out here:
Kedarkantha Trek Vlog

Client-Server Architecture Made Easy

2021-03-31T18:42:00.008-04:00

Servers Made Easy:

Whenever you visit a website, you see many pictures, videos, text etc. This is known as the data of the website. If you want to see this data every time you visit that website, the website’s data should be stored in a device that is connected to the internet at all times. These devices are called “Servers”. These servers store the data of the website and are connected to the internet so that the website works 24/7.

In simpler terms, A server is a computer that stores data and sends it when it is asked for.

Based on these observations, let’s derive the features of a server.

Characteristics of a Server:

1. Servers always wait to serve the requests.
2. In order to serve the request, a server may communicate with other related servers as well.

But the question is, who asks for the data from the server?

Clients Made Easy:

When you type ‘facebook.com’ and hit enter, the data of the website
should get loaded from servers, but who’s asking to load the data of
the website?
It’s your PC (web browser), which is in fact also known as “Client” in this case.

Based on these observations, let’s derive the features of a client.

Characteristics of a Client:

1. Requests the data from the server.
2. Waits for the server to receive data.

Client-Server Made Easy:

Now that you know about clients and servers, let’s combine both of them and
look at what is known as “Client-Server Architecture”.

Let’s take a very general example.

If you want to get something, you must ask something. Similarly, if you want to visit a website, you are in turn asking to load the data of the website. Thereafter, the data is fetched from the web servers and finally, the website is loaded. Here there are two main roles involved – The client, which is requesting to load the website and the Server, which is presenting the data that is requested by the client.

This coordination between Client and Server is simply known as “Client-Server Architecture”

Understanding Ports

2021-03-13T00:39:00.007-05:00

Let's say you're using Twitter, Facebook, Youtube, all at once. You are commenting on someone else's post on Facebook, tweeting something on Twitter and listening to a song in the background on Youtube simultaneously.

In this case, your device is connected to all three servers i.e, Twitter, Facebook and Youtube servers and also you're receiving data from all three servers at the same time.

Now, if all this data comes together, then will the device not get confused as to which data is from which server?

Similarly, if requests from multiple devices are going to a server, will the server not get confused as to which node requested which information?

Well, it does!

And to solve this problem, all devices i.e, both clients and servers are assigned Ports.

Let's take another example, In a shop, there are three different counters namely Electronics, Homecare and Clothing. These three different counters provide different services and are selling different things.

These counters can be assumed as Ports.

Different services/applications run at each port and listen to or capture the data and requests coming from each port.

Ports are classified into 2 types:

1. Hardware ports:
These ports provide a gateway to get inside a system and interact with hardware.
Eg: USB, HDMI etc

2. Software ports:
These ports provide a gateway to get inside a system and interact with software.
Every software port is denoted by a number between 0-65535.
Each software port takes us to a different application/service.

If a data packet is travelling from client to server, this data packet essentially contains four pieces of information in it.

i) IP address of the server.

ii) Port number of the server.

iii) IP address of the client

iv) Port number of the client

This combination of IP address:Port Number is known as Virtual Socket.

How to Start Your Own Blog For Free?

2021-02-25T16:43:00.001-05:00

I have started this blog on April 23, 2020. Recently, This blog crossed an overall of 10k+ views. So I believe, I am in the right position to guide you regarding how to start your own blog for free.

Many of my friends have asked me questions like:

How to start a blog?

Is it free of cost?

How and where should I publish my blog?

and the list goes on...

By the end of this post, I assure you that you will get better clarity on how to start your own blog.

Let's start.

Basically, there are two ways that you can start your blog.

Paid Blogs
Free Blogs

Paid Blogs:

You need to purchase your own domain name (For example, www.sairohith.com, Here 'sairohith' is the domain name) and also buy a web hosting service for your blog from reputed websites like GoDaddy, Wix etc.
This literally means that the blog is completely under your control. Once you purchase your own domain name along with good web hosting, you can start writing by choosing a template of your choice.

I'm not going to discuss the details of paid blogs further because I'm quite inexperienced with it.

As our main focus is on how to start a blog for free, let's dive into our topic.

Free Blogs:

You can choose your own domain name, but there will be an extension of the service owner.
For example, www.sairohithkaranam.blogspot.com. Here, I have chosen my domain name to be 'sairohithkaranam', but I cannot remove 'blogspot.com' from my website address as it is the extension of the service owner.
There are famous websites like Blogger, WordPress which offers services to start your own blog free of cost.
You don't need to buy any web hosting service for maintaining these type of blogs. Everything is managed by the service owner.
Just choose your domain name, choose a template, write and publish.
If your blog gets more and more popularity with time, you can just buy a domain name of your own for the same website from the service owner without any disruption, which means, you will no longer have a 'blogspot.com' extension in your blog's URL.
Last but not least, you can also apply for Google Ads for advertising in your blog once your blog gets enough popularity via views and followers. In this way, you can also make money from your blog.

Why do I recommend beginners to start free blogs?

If you are just new to blogging, then you are just trying to explore writing blogs. So, to gain experience without affording any money is kind of a great start for your blogging career.
If at all you want to start a paid blog anyway, why not gain adequate experience by writing free blogs and then invest money in a paid blog from your experience?

Now that I've given you a brief overview of free blogs, let's actually see it in a more precise way.

Step 1:
Be more specific about what type of content you want to write in your blog.

Is it related to studies? If studies, which subject?

Is it related to beauty?

Is it related to motivation?

Or is it a mix of different categories?

Step 2:

Create an account on Blogger or WordPress

If you want a minimalistic view of your blog, if you are someone who wants your blog to be simple yet elegant, create an account on Blogger.

If you want a more attractive look and creative designs for your blog, create an account on WordPress because WordPress has more attractive themes than blogger.

Step 3:

Name your blog.

Make sure your blog's name matches the content published on the blog.

Step 4:

Choose your domain name.

Choose your domain name very carefully, because you cannot modify your domain name once created. A domain name is literally the identity of your blog.

Step 5:

Choose a template/theme of your choice.

Choose a theme that looks well on both laptop and mobile.

Step 6:

Start writing your first post on your own blog and hit the publish button.

That's it.

Wow, that's amazing. You just learnt how to start your own blog for free!!

How do White Hat Hackers Hack a System?

2021-02-10T05:16:00.007-05:00

Who are White Hat Hackers:

White hat hackers are legal security professionals who work for protecting organizations from cyber threats.

Remember, the only difference between black hat hackers and white hat hackers is the intention behind the hack. Both hack the computer systems, but white hat hackers hack for protecting the organization from cyber threats whereas black hat hackers hack for their own benefit illegally.

In the previous post, we have discussed how do black hat hackers hack a system. If you haven't seen it yet, I suggest you read that before reading this.
How do Black Hat Hackers Hack a System?

Now lets finally get into our topic - How do White Hat Hackers Hack a System?

Step-1: Legal Documentation

White hat hackers make sure they sign Memorandum of Understanding (MOU), which is a document that describes the testing activity and the steps that will be taken, on a legal paper.
Along with MOU, there is another document called the Non-Disclosure Agreement (NDA), which is signed by both the parties (White hats and Organization). NDA is proof that white hat hackers will not disclose any details of the activity, cost and vulnerabilities of the organization to third parties.
Finally, A Financial Agreement is made which puts the cost to perform the activity on a legal paper.

Step-2: Scope Assessment

White hat hackers and the organizational client decides the scope of the audit and also the time required for the audit.
For example, if the client has a website, white hat hackers discuss which part of the website is to be tested (Scope) and the time required to perform the activity.

Step-3: Information Assessment

White hat hackers gather the information from the client and from various data mining tools like Maltego etc.
For example, if a part of the website is to be tested, then they collect information like on which server the website is running, alternate domain addresses for the website etc.

Step-4: Vulnerability Assessment

After gathering the required information in Step-2, white hat hackers scan for vulnerabilities from the gained information using manual and automated tools.
All the vulnerabilities found during this process will be documented in a clear and precise way.

Step-5: Penetration Testing and Gaining Access

After finding the vulnerabilities, the white hat hacker performs malicious activities implicitly to check the level of system compromise and documents every detail of the activity and writes Proof of Concept (POC).

Step-6: Report Generation

Now after completing the penetration testing of the system, a clear report is been made with vulnerabilities found, their impact on the organization and measures to be taken to avoid exploiting those vulnerabilities.

Step-7: Patch Assistance

After showing the report of vulnerabilities and their impact on the organization, the client decides which vulnerability should be patched and which should leave behind depending on the cost and effort to patch. Now the developer starts patching.

Step-8: Revalidation

After the developer patches the vulnerabilities, white hat hackers revalidate the system if it's been properly patched.

Now after reading the two posts, you've known the difference between black hat hackers and white hat hackers and the procedure followed by black hat hackers and white hat hackers to hack a system.

How do Black Hat Hackers Hack a System?

2021-02-08T04:42:00.001-05:00

Who are Black Hat Hackers?

Black Hat Hackers are those who use their knowledge to hack computer systems for their own profit illegally.

How do Black Hat Hackers Hack a System?

Step-1: Information Gathering and Reconnaissance

Let's assume if a hacker is trying to hack a website, he gathers information like on which server the website is running, the programming language behind, user base and architecture of the website.

Step-2: Vulnerability Assessment

Vulnerabilities are nothing but security loopholes or weak entry points.

After Step-1, the hacker performs vulnerability scan using manual or automated tools. These tools run through the entire website and at the end, it gives a report of possible vulnerabilities. Meanwhile, the hacker also checks for bugs and errors on the website.

Step-3: Penetration testing and Gaining Access

Now after finding vulnerabilities in the Step-2, the hacker may exploit the vulnerabilities to gain access.

Step-4: Escalating Privileges and Maintaining Access

In this step, the hacker is partially inside the system. In this step, the hacker tries to gain full control of the system (Admin-level privileges). By gaining admin-level privileges, the hacker installs backdoors to the system.

Backdoor is a program that lets the hacker access the system any time as long as they are installed.

Step-5: Clearing tracks

After doing all the malicious activities in the system, the hacker deletes all server log files, deletes additional users created and reverts the server as it is before the hack.

In the next post, we will discuss how do white hat hackers or security experts hack a system.

Remember, the only difference between white hat hackers and black hat hackers is their intention behind the hack.

Types of User Accounts in Linux

2021-01-12T01:49:00.003-05:00

User accounts represent identities that authenticate to the system and can use authentication credentials to do specific tasks.

Individuals who will be using the Linux computer should have their own unique user accounts. Administrators will use these accounts to control the user's access to files, directories, and commands on the system. Each account is referenced by the system using a user ID (UID), rather than a name. Names are used for the convenience of the users.

User accounts have several attributes, including password information, group memberships, expiration dates, comments, etc.

Types of User accounts:

There are three different types of user accounts:

Root
Standard user
Service

Root User Account:

There are two roles played by the root user.
i) As a local administrator.
ii) To provide a security context for some applications and commands.
A user logged on as root can do administrative tasks such as password resets, system configuration changes, user account management, etc.
It is a bad practice to log on to any system with administrative credentials directly.

Standard User Account:

Standard user accounts represent regular system users who may log on to run applications, configure databases, build websites, etc.
Most tasks that a user should be doing on the system should only require standard user account privileges.

Service Account:

Applications also consume resources on the system, so they are often represented by their own service accounts.
These accounts are usually specific to the service (such as the httpd web service or a database service).
They are disabled for regular log on, and the accounts are usually created as part of the service installation process.

10 lessons I have learnt in 2020...

2020-12-25T14:54:00.012-05:00

2020 is a year of shocks, surprises, learnings and a lot of introspection for me.

I know with the arise of corona pandemic, many people have lost their lives, lost their jobs, lost their own families but still, there are a lot of things we need to be grateful for. For example, at this moment, you are alive, you are reading this, your senses are working properly and above all, your health is perfectly alright in spite of the pandemic.

Now tell me, how many good things are there that we need to be grateful for amidst of corona chaos?

Every year is an experience we gain for the future, experience from the mistakes that we've done, experience from the way we have responded in a particular situation and experience from our self-fulfilling prophecies.

So like everyone else, this year has really taught me some valuable lessons which I believe are the first step to achieving my goals.

So I thought, why not share my experience of this year with people so that they may learn something out of my experience?

As someone rightly said, "Wise people are the ones who gain experience from their own, wiser people are the ones who gain experience from their own and from others experience as well".

Lesson 1:
Everything outside is not in your control, be it people or situations. The only control you have is on yourself, your only control is in the way you respond to people or situations.

For example, Did you expect the rise of corona pandemic? No. Did you expect more than 6 months of lockdown? No. The most important question is, Do you have any control over these situations? Obviously, No! Then what is in your control? Your only control is to take care of yourself by following all the measures.

Lesson 2:
Self-care is the first step for achieving anything in your life, literally anything.

So, what does self-care mean? Self-care is to take care of your body and mind. Many people eat a nutritious diet for maintaining a great physique, but how many are taking control over their mind? How many are in charge of their emotions? You are not only what you eat, but you are also what you read, watch and listen. Take care of the information you consume on social media platforms like Instagram, Facebook. With each and every bit of information you see on social media, you are literally feeding the raw material for the basis of your thoughts which in turn becomes the foundation of your attitude and attitude becomes the foundation of your success.

Tip: Try social media detox for one day in a week.
Lesson 3:
Nothing can replace two things in life: Discipline and Hard work.

Even if they are replaced, the quality of success will be of poor quality and failure is certain in the future.
Lesson 4:
Stop comparing your progress with that of others.

So basically, why do we compare with others? Because if someone is ahead of us, we strive to get ahead of them. Why do we strive to get ahead of them? Because your mind only needs pleasure, nothing else. Your mind doesn't bother what other emotions (Jealousy, ego) you are creating while striving to get ahead of someone else.

This doesn't mean you should stop working hard and sit like a rock.
The point is, you should compare your progress with only yourself, your past self. Your goal should be to be better than what you were yesterday.
Agreed that our grades, marks and ranks are calculated by comparing with others. But here the resources are limited, there are only limited IIT seats, there will be only one 1st ranker, not in thousands. But ultimately, it's your choice, do you want to achieve success with filled emotions of compassion and respect or do you want to achieve success with filled emotions of jealousy and insecurity?

Everyone's life journey is unique and beautiful in its own way. So don't degrade yourself by comparing your beginning journey with someone else's mid-journey.
Lesson 5:
Patience and Perseverance are the vital ingredients for the recipe of success. Cultivate them more.

Self-control also comes under this category. Success is not measured by how high we go up in life, but how many times we bounce back when we fall down. To bounce back every single time you've failed, you need the patience to wait for success and also perseverance to achieve success regardless of how many times you fall down.
Lesson 6:
Any type of emotions like anger, happiness, love, jealousy etc is not created by something or someone. They are created by YOU in response to something or someone.

I'm pretty sure that most of you have your mobile phone in your hand. How did you feel when you first purchased it? Obviously, super happy, new features, new phone. Now pause for a moment and think, Is this phone really making you happy or you are creating happiness in response to the phone's features and looks? In the same phone, if you get one message which is slightly disturbing, how do you feel? Happy to sad, sad to angry, angry to jealousy etc. But the phone is the same, right? Then how come you are not happy?

The point is, anyone or anything doesn't have the power to create an emotion within you unless you accept and allow. In the case of a mobile phone, you created the thought "My phone has got some really amazing features, huh, better than my friend's mobile". This single thought created pleasure within your mind which eventually lead to happiness.

Tip: Start recognizing material things which you feel makes you happy like LED TV, Air Conditioner, your marks, your physique etc
Lesson 7:
Every thought you create is an energy which has a certain frequency and this energy radiates into the environment and influences others state of mind.

You don't believe me? just click on the below link after reading this post or you can directly search in google.

Click here

So, take care of your thoughts because your thoughts not only affect you but also the universe.
Lesson 8:
What you do is what matters, not what you think or say or believe or plan.

This lesson has really made a huge impact on my perception. Literally, I am good at planning everything nicely, but when it's time to act, I still plan. Is this planning has of any use without necessary action? NO.

No matter what you think or believe about yourself, your action tells everything.
Lesson 9:
The power of meditation.

I know this seems like an old-classy word when you listen to the word 'meditation'. But the truth is, no, it's not. I can't say anything about meditation, because it is a feeling which has to be experienced by one's own self. Even if you read a thousand books on how to meditate, you can't just really get that essence unless you sit and try to meditate.

Simply put, Meditation is a way of calming your mind, being aware of your thoughts either distractive or productive and slowly introspecting your emotions and channelising those emotions in the right way possible. Complicated, huh?
Trust me, it's not.

Tip: Try meditating for 10-15 minutes and observe how does it feel afterwards, for a week. Come on, take it as a fun challenge!
Lesson 10:
Once you form your habits, your habits form you. Read again.

Why does every successful person in the world have a set of common good habits? Why do our parents worry so much when we indulge in not-so-good habits? Why?
Because every choice has a consequence and we have control only on our choice but not on the consequence of the choice, your only choice is to choose which type of choice.

We can't really feel inspired and motivated every single day. No, humanly not possible. That is why it is important to form productive habits beneficial to your well being because forming a habit is your choice, and every choice has a consequence. Forming positive habits leads to positive consequences.

Some of the habits I started learning this year:
1. Three minutes of gratitude after you wake up for all the good things you have.
2. Drink 1 litre of water every morning.
3. Meditation.
4. Prayer before eating.
5. Reading books.

These are only a few major learnings which literally made me question my beliefs and perceptions.

I hope you got to learn at least a few from the above.

Also, Wishing everyone a HAPPY NEW YEAR, This new year will be the beginning of new YOU. Cheers!

Have you lost your track? - Recharge and Reflect Now

2020-11-10T02:50:00.008-05:00

My sincere apologies to everyone for me being inconsistent in the blog. I am swamped with my semester academics as well as with personal issues. I try my level best to be consistent from now.

Okay then, let's start this comeback with a powerfully packed post.

We all make resolutions, we all make up our mind so strong that our desire to adopt new habits and the want to change seems to be at the zenith. But somewhere along the way, we lose our motivation to try and get stuck in a helpless and baffling condition.

This post is intended for everyone who has lost their track of what they are doing and to refill their minds with unlimited hope and enthusiasm.

Don't stress yourself too much because no matter how bad the situation is, it will change.
When you face difficult times, know that challenges are not sent to destroy you. They are sent to promote, increase and strengthen you. Embrace your challenges.
Never regret a day in your life. Good days give happiness, Bad days give experience, Worst days give lessons to learn in life and best days give beautiful memories.
Life is like a book. Some chapters sad, some happy, and some exciting. But if you never turn the page, you will never know what the next chapter holds.
Every transformation begins with an intense want to change. How deep is your want?
Don't dwell on what went wrong. Instead, focus on what to do next. Spend your energies on moving forward.
Find the courage to keep trying, even when it seems like no progress is being made.
Believe so firmly that there is no such thing as failure, You either win or you learn.
A ship is always safe at shore but that is not what it's built for. Face challenges, make mistakes, learn from your mistakes, grow.
You can't go back and change the beginning but you can start where you are and change the ending. Don't let self-doubt and fear hold you back. You can and you will achieve whatever you wish to.

To conclude, It is really okay not to feel motivated every day and it's quite natural being human. All that matters is that you pick yourself up and get things done, no matter what mood you are in. If everything was perfect, you would never learn and grow. Every obstacle you face now is really an opportunity. It is your choice to sit idle and dream or to refill your mind with enthusiasm and become unstoppable.

Every day you are born again, Start now and get back on track.

Try to read this post as many times as possible till you get a sort of clarity in your mind.

Types of Communication Links

2020-09-08T10:22:00.010-04:00

A communication link is a communication channel that connects two or more communicating devices. This link may be an actual physical link or it may be a logical link that uses one or more actual physical links.

There are majorly 4 types of links. They are:

1. Point-to-Point Link: This link connects two devices without any device in between them.

2. Transient Link or Broadcast Link: This link connects two devices with the support of other devices as well. In transient network, data can enter or leabve from any router.

3. Stub Link: Data enters and leaves through only one router. Stub network is Unidirectional.

4. Virtual Link: Virtual networking enables devices across many locations to function with the same capabilities as a traditional physical network.

useradd command

2020-09-08T09:10:00.046-04:00

Use of this command:

'useradd' command is used to add a new user into the system. In other words, it creates a new login account for a different user.

Remember that only the root user can add new users into the system.

You can check who are the existing users in /etc/passwd file

To simply add a user to the system, this command is used:

useradd virat

This command adds the user named virat into the system and you can check whether virat is added or not in the /etc/passwd file.

This is just a basic way of adding users into the system.

Now let us explore the various options of useradd command.

But before going to that, let us understand all the fields in /etc/passwd file.

There are 7 fields in /etc/passwd file for every user.

1. Username: Name of the user.

2. Password: This password is not visible. (marked x)

3. UID: User ID

4. GID: The group ID of which the user belongs to.

5. Comment field: Here the user can write anything which he/she wants to. This is optional.

6. User home directory: The user's home directory is shown in this field. By default, the user's home directory will be /home/username.

7. Default shell: This shows the name of the default shell with which user interacts. By default, it is bash shell.

Now that you've known about the fields of /etc/passwd file, let us explore various options of useradd command.

1. useradd -c: To add a comment

2. useradd -d: To set a home directory. If you don't set, the default one will be /home/username

3. useradd -u: Customize UID, set UID of your choice.

4. useradd -g: Add the user to an existing group with that existing group's GID.

5. useradd -G: Add the user to supplementary groups, i.e, other than the default primary group.

6. useradd -e: Add the user with an expiration date. After the specified date, the user is disabled.

7. useradd -s: sets the default shell for the user. If this is not set, the default shell will be bash.

Fun part:

Which command is used to create a user by taking password on the spot?

Post your answer in the comment section if you got it.

Purpose in Life vs Purpose of Life

2020-08-22T08:39:00.003-04:00

A gentle disclaimer, This post is only written on the basis of my thoughts and perspectives. It is not intended to hurt anyone's beliefs and traditions.

Okay, let's start.

We study at prestigious universities, we get the highest paying jobs, we get lots of money which is well enough to buy every single thing for our own comfort, our parents will be very proud of everything we have achieved and a lot more praise from the society. Are these enough for your life to be successful?

If you said no, you're on the right path.

But if you said yes, Think again!

Today we are in the year 2020, let's move a 1000 years back. Because you were born in the 20th or 21st century, you are struggling to become a doctor or an IT professional. What if you were born 1000 years ago? Well, you might opt fishing as your career, right?

What did this symbolise?

Our purpose in life, which means it is the purpose which we should fulfil to make a living for our life keeps on varying.

Today, you are struggling to become a doctor or an engineer, future generation kids may struggle to become something which we never thought of becoming.

Unfortunately, while achieving our purpose in life, we completely have forgotten our purpose of life.

What is our purpose of life?

If you want a single line difference between purpose in life and purpose of life, here you go,

Purpose in life: To make a living for your life
Purpose of life: How to live your life

Amazed, surprised, confused?

Well, we thought both are the same. We thought that our only purpose is to be in a good position which uplifts our family's financial status.

The tragedy is that the whole universe is running after the purpose in life leaving behind the purpose of life.

Starting right from schools, everyone is taught to become successful. But successful in what?

Successful in our achievements or Succesful in life?

Successful in life means to have a perfect balance between our purpose in life and purpose of life.

If I talk about our purpose of life, you will be studying this post for at least 3 hrs. So, I would like to say it as short and crisp as possible.

As per my learnings till date, Our purpose of life is to know who we are and live our life with values.

In today's generation, almost everyone is living their lives with only one tagline - 'Life is a competition'.

Even our teachers and elders taught us that life is a competition because their parents taught likewise!

But in reality, everyone's pace is different, one cannot be as capable as another. Because we are living our life as a competition, there is so much chaos all around the world right now.

But once if we think about our purpose of life, everyone starts living their lives with only one tagline - 'Life is a beautiful experience of caring, sharing and co-operating with others'.

We will be learning everything slowly about our purpose of life alongside holding on our purpose in life in upcoming posts.

Summary:

Purpose in life is very important without which we cannot live. But purpose of life is equally important in our lives. Because our purpose in life is visible to us in the form of our achievements and praise from others, we thought that this is the only purpose. But in reality, there is another purpose, which is our purpose of life. Purpose of life is hidden but forms the basis of every achievement we achieve and fosters our every relationship with others.

Try to introspect yourself by doing meditation.

PS: Happy Ganesh Chaturthi : )

PKI & its components

2020-08-11T12:55:00.002-04:00

crux points:

PKI stands for Public Key Infrastructure.
A public key infrastructure (PKI) is a system that is composed of certificate authorities, certificates, software, services, and other cryptographic components, for the purpose of enabling authenticity and validation of data and entities.
PKI can be implemented in various hierarchical structures and can be publicly available or maintained privately by an organization.
As its name implies, a PKI implements asymmetric cryptography for the encryption and decryption of network data, including transactions over the Internet.

In simpler terms, just remember that PKI is a set of certificates, services etc along with essential cryptographic components used for the authenticity of data.

There are many cryptographic components that comprise PKI. Some of the important ones are-

Digital Signature:
The sender creates a hashed version of the message text and then encrypts the hash itself with the users private key. The encrypted hash is attached to the message as a digital signature.
Digital Certificate:
A digital certificate is an electronic document that associates credentials with a public key.
Certificate authority(CA):
A CA is a server that issues digital certificates for entities and maintains the associated private/public key pair.
Certificate Signing Request (CSR):
A CSR is a message sent to a CA in which an entity applies for a certificate. It typically includes information that should go into the entity's certificate, like its public key, digital signature, and other identifying information.

Intrusion Prevention System (IPS)

2020-07-14T03:47:00.011-04:00

What is IPS?

An intrusion prevention system (IPS) is a security appliance that monitors and evaluates a system for signs of attacks in progress, and can actively block traffic that it determines is malicious.

IPSs are similar in purpose to firewalls in that both can stop unwanted traffic from entering a network. However, they have some key differences.

Here is my post about a basic layout of firewalls if you haven't seen it yet:

https://sairohithkaranam.blogspot.com/2020/07/what-is-firewall.html

A firewall is like a security guard who lets guests into a building based on whether or not they match predefined rules. An IPS is more like a second security guard inside a building. Even if the outside guard (the firewall) lets someone in, the inside guard (the IPS) will watch that guest for signs of suspicious behaviour. If the guest exhibits a repeated pattern of suspicious behaviour, the inside guard will kick them out.

In other words, an IPS is a second layer of defence that monitors traffic that makes it past the firewall, looking for signs of anomalous behaviour.

The other major difference is that IPSs are only concerned with managing incoming traffic, whereas firewalls apply to both incoming and outgoing traffic.

There are many IPS solutions available. Two common third-party solutions are DenyHosts and Fail2ban, both of which examine log files for anomalies.

Note: An intrusion detection system (IDS) is the same as an IPS except it does not actively block traffic, but only alerts personnel.

What is a Firewall?

2020-07-13T22:30:00.006-04:00

A Firewall is a software program or a hardware device that protects a system or a network from unauthorized access by blocking unwanted traffic.

A firewall can allow or deny incoming and outgoing traffic based on a set of rules that are either explicitly configured by an administrator or which are active by default.

There are three main generations of firewalls:

Packet filters (first generation): These firewalls make decisions based on rules that correspond to one or more network packet attributes. These rules appear in the form of an access control list (ACL). Packet filtering firewalls are also called stateless firewalls because they can only inspect a packet in isolation, and cannot determine what has come before that packet that might provide valuable context.

Stateful firewalls (second generation): In contrast to packet filters, stateful firewalls can identify past traffic that is related to a packet. This means that a stateful firewall can view the entire conversation of a transmission, such as the three-way TCP/IP handshake. Stateful firewalls can, therefore, make more informed decisions about what traffic to deny and what to allow.

Application-layer firewalls (third generation): These firewalls can inspect the contents of application-layer traffic (e.g., protocols like HTTP and FTP) and make decisions based on these contents. An application-layer firewall can detect attempts to bypass traditional filtering and stateful inspection that leverage known software exploits.

Static Initialization Blocks

2020-07-08T02:44:00.003-04:00

Basic Properties of Static Variables:

A static variable is a variable which is initialized only once at the start of execution.
Static variable belongs to the class and not to the object of the class.
Static variables should be initialized before the initialization of instance variables.

If we know the value of a static variable, then we can initialize it in one line.

Like this :

public static int a = 20;

Here, we initialized the value of 'a' as 20 directly.

But what if we want to initialize that static variable when a certain condition is met?

For example, I want to initialize 'a' as 20 when the other value 'b' is greater than zero. If 'b' is less than zero, I want to initialize 'a' as 30.

How do we do this?

That's where the role of static initialization blocks comes into play.

A Static Initialization Block is a normal block of code enclosed in braces and preceded by the static keyword.

There can be any number of static initialization blocks in a class. They are called in the order in which they are written in the program.

An Example Demonstrating Static Initialization Blocks:

class StaticDemo{

static int a;

static int b;

//Static Initialization Block starts

static{

Scanner scan = new Scanner(System.in);

System.out.println("Enter the value of b: ");

b = scan.nextInt();

if(b >= 0){

a = 20;

}

if(b < 0){

a = 30;

}

public static void main(String... args){

System.out.println("Value of a is: "+ a);

}

From the above program, we can see that the value of 'a' is 20 when the value of 'b' is greater than or equal to zero. Similarly, the value of 'a' is 30 when the value of 'b' is less than zero.

6 Things To Do On Your Birthday

2020-07-07T07:33:00.005-04:00

Birthday vibes are so pure, light and naturally beautiful to feel.

Wishes and blessings from our family and friends make us feel happier throughout the day.

Nowadays, with the advancement of technology, we share our birthday moments with our closed ones via Whatsapp/Instagram status.
We feel that something is pure in the environment.

Why do you feel that way?
The same house, the same people, the same environment and the same you.
But why do you feel a little different on your birthday involuntarily?

Ever thought about it?

The truth is, our mind is in a pure and elevated state which is making us see every external thing beautiful.
When every external thing or person seems to be beautiful, there will be only happiness.

We ignore the fact that our birthday is a new beginning.
We ignore the fact that our birthday is a fresh start.

We ignore the fact that our birthday is a new opportunity given by the supreme power.

We simply enjoy the day with our family and friends, eat and drink to the peaks and end our birthday with deep sleep.
The next day we wake up, our mind is again in the helter-skelter mode and continue our daily routine with our deeply ingrained habits.

This is not the right way.

Birthday means Birth + Day, You were born on this day!

Don't you have a feeling to lead a new life, change your old habits and empower yourself from the day you were born?
If yes, then why are you not thinking about it?

Its time to think and introspect yourself.

Here are the 6 things to do on your birthday.

Start your day by being grateful to everything and everyone.
Starting from your pillow to the dress you wear, starting from your parents to friends, starting from your weaknesses to strengths, starting from your failures to successes, everything and everyone. No matter how bad it seems to you, you have to do it.
Because there are many souls out there who are not even getting half of what you are getting and what you've got.
Dedicate at least half an hour of your time to god.
Imagine a day without oxygen. Will you be able to survive?
Imagine a day without water. Will you be able to live?
Earth may be created by a random collision as stated in the big bang theory. But the truth is even that random collision is created by the supreme power which is beyond human power. That supreme power is termed as 'God'.
God is a collection of purity, divinity and peace.
No negativity throughout the day.
No matter how worse the situation is, no matter how unfair the other person's behaviour is with you, don't allow your mind to think even one single negative thought about that situation or the person. Believe that it is all for your good and cross the situation with dignity.
List out your weaknesses, faults, addictions which you have to work upon.
By doing this way, you will at least have clarity from where and what you should start to work.
Strong and Firm Resolution.
Birthday resolution means to take a goal and work upon it at least till your next birthday.
Once you have decided your goal based on your weaknesses and addictions, you have to fix your mind in such a way that nothing can tempt or deviate you from your goal. This is known as a strong and firm resolution.
Remember, Taking resolutions is very easy, but implementing them is very difficult. That is why great saints say that self-control is the key to achieving your goals.
Enjoy your birthday to the fullest.
Your birthday is not going to come until 1 year. So, along with the above 5 points in your mind, you should enjoy your birthday with your family, friends and loved ones to the fullest.

Maybe I've missed some more important points, it's up to you if you want to add any other points.

In this way, you should celebrate your birthday with proper vision in your mind for a better future.

Introduction to Subnetting

2020-07-05T10:32:00.013-04:00

What is subnetting?

Why do we need subnetting?

What is the benefit of subnetting?

I know there are a whole lot of questions running in your mind right now.
Hold on, You will get to know all the answers by the end of this post.

Let's dive in.

What is Subnetting?

In simpler terms, The process of dividing a larger network into smaller sub-networks is called 'Subnetting'.

These smaller sub-networks are called 'subnets'.

The formal definition says, The process of converting host bits to network bits is known as Subnetting.

Now that you've understood what subnetting is, let's now see what is the cause for subnetting.

Why do we need Subnetting?

We all know that an IP address is a combination of a network ID and Host ID.

IPv4 address is of 32 bits.

Class A IP consists of 8 bits of network id and 24 bits of host id.

Class B IP consists of 16 bits of network id and 16 bits of host id.

Class C IP consists of 24 bits of network id and 8 bits of host id.

So, Class A IP has the capacity to hold 2^24 - 2 = 16,777,214hosts (As there are 24 bits in host id part)

Class B IP has the capacity to hold 2^16 - 2 = 65,534 hosts (As there are 16 bits in host id part)

Class C IP has the capacity to hold 2^8 - 2 = 254 hosts (As there are 8 bits in host id part)

Everything's fine till here.

Now the scenario comes, Imagine I want to build a network that will support up to 30 devices in four different segments. Without subnetting, I will need four (4) Class C networks to support this design. For example:

Network #1: 192.168.1.0

Network #2: 192.168.2.0

Network #3: 192.168.3.0

Network #4: 192.168.4.0

Each of these networks will support 254 IP addresses leading to wastage of (254 * 4) – (30 * 4) IP addresses i.e. 896 IP addresses!

If you look at the design requirement of 30 hosts per network, you will discover that I only need 5 bits in the host ID portion of a Class C network to satisfy my requirement.

That is, 2^5 - 2 = 30 hosts.

This means I still have 3 bits unused and with subnetting, I can use those three bits to create smaller networks. For this example, let’s take the 192.168.1.0 network:

By borrowing 3 bits, I can create 8 subnets:

192.168.1.0

192.168.1.32

192.168.1.64

192.168.1.96

192.168.1.128

192.168.1.160

192.168.1.192

192.168.1.224

With subnetting, not only have we used only one Class C network, we have created 8 subnets from that network, each one supporting up to 30 hosts! We can use 4 of these subnets for our network and reserve the remaining 4 subnets for future expansion. This results in great waste reduction – from 896 wasted IP addresses to 120 reserved IP addresses.

I know it seems so messy to understand if you are a beginner, but it becomes so easy with repetition.

Benefits of Subnetting:

Minimises the wastage of IPs.
Maintenance is easy for smaller networks.

We will discuss the types of subnetting and other topics related to subnetting in future posts.

Let go of jealousy...

2020-07-01T03:03:00.008-04:00

Before going further, Let's be clear with the definition of Success.

Success doesn't mean just to achieve money, fame, respect.

Success means to achieve whatever you wish in the right way by being emotionally well.

Now that you are clear with the definition of success, let's move further.

When our mind gets disturbed by others progress and achievements, this unbearable feeling is termed as 'Jealousy'.

People think that it is so natural to get jealous when we see someone who is much better than us.

Let me give you an example.

30 years ago, Blood Pressure/Diabetes is not natural.

But why do we say that it is so natural to get BP/Diabetes now?

20 years ago, Stress is not natural.

But why do doctors say that it is so natural to get stressed now?

Similarly, many years ago, Jealousy is not natural.

But why do we say that it is so natural to get jealous now?

The answer is pretty simple.

BP/Diabetes became more and more common among almost everyone.

Stress became a part of almost everyone's life.

Jealousy developed so much in almost everyone's life.

When the problem is common with almost everyone, we slowly learned to term it as 'Natural'.

We completely forgot the ill effects which it is causing or will cause and started believing that jealousy is so natural.

We have to Pause and Check for a moment.

Our mind got so habituated to think like this-I want to go ahead of someone who is better than me as soon as possible so that I will be successful in my life.

This is a big misconception created by someone.

If the goal is yours,

If the plan is yours,

If the hard work is yours,

If the success you are trying to achieve will be yours,

Then Why should you ruin your mind by seeing others progress?

The problem started because we were not thinking of increasing our own capacity. Instead, we are thinking of being better than other's capacity.

By thinking this way, we are depleting our own capacity.

By creating jealousy in our mind, we develop our ego in such a way that it decreases our willpower and soul power.

When our willpower and soul power decreases, it decreases the efficiency of our performance.

No matter how smart and intelligent you are, there will be always someone who is better than you.

This is a pure fact that must be accepted and remembered all the time.

Even if you succeed by following this harmful route, it's no longer considered 'Success'.

There is no essence of being successful in this way.

Ranks and grades are important but the comparison is limited.

When comparison exceeds its limit, our mind gets disturbed which in turn leads to 'Jealousy'.

Remember, If you want to be successful in any field, you should only compete against yourself.

Externally you may be competing with thousands of people around the globe, but internally your utmost competition should be only 'YOU'.

It's time to teach your mind the new and right way of thinking to achieve real success.

PS. Difficult to start, but not impossible to start.

Brief Overview of Link State Routing

2020-06-24T21:05:00.005-04:00

Previously, we have discussed distance vector routing.

Here is the link if you haven't seen it yet -

https://sairohithkaranam.blogspot.com/2020/04/distance-vector-routing.html

Now we are going to see about Link State Routing which is also a category of intradomain routing.

In Link state routing, four sets of actions are required to ensure that each node in the routing table is showing the least cost to reach the other node.

Four sets of actions are:

Creation of the states of the links by each node (router), called Link State Packet (LSP).
Sending LSPs of each router to every other router through a mechanism called 'Flooding' in an efficient and reliable way.
Formation of shortest-path tree for each node (Using Dijkstra's algorithm).
Calculation of routing table based on shortest-path tree.

Note:

A small packet that consists of routing information is called Link state Packet (LSP).
When LSPs are generated?
i) Whenever there is any change in topology.
ii) Generated on a periodic basis.

You can see the differences between distance vector routing and link-state routing here:

https://sairohithkaranam.blogspot.com/2020/06/differences-between-distance-vector.html

Differences between Distance Vector Routing and Link State Routing

2020-06-24T20:48:00.008-04:00

Major Differences between Distance Vector Routing and Link State Routing are as follows:

Distance Vector Routing	Link State Routing
1. Bandwidth required is less (Local Sharing)	1. Bandwidth required is more (Flooding)
2. Uses the Bellman-Ford algorithm	2. Uses Dijkstra's algorithm
3. Traffic is less	3. Traffic is more
4. Existence of count to infinity problem	4. No count to infinity problem
5. Eg: RIP (Routing Information Protocol)	5. Eg: OSPF (Open Shortest Path First)

What is IAM?

2020-06-09T08:18:00.004-04:00

One major dimension of cybersecurity is identity and access management (IAM). You'll configure various IAM solutions in order to better protect your Linux systems against unauthorized access.

crux points:

Identity and access management (IAM) is a security process that provides identity, authentication, and authorization mechanisms for users, computers, and other entities to work with organizational assets like networks, operating systems, and applications.
IAM enables you to define the attributes that comprise an entity's identity, such as its purpose, function, security clearance, and more.
These attributes subsequently enable access management systems to make informed decisions about whether to grant or deny entity access and if granted, decide what the entity has the authorization to do.
For example, an individual employee may have his or her own identity in the IAM system. The employee's role in the company factors into his or her identity, like what department the employee is in, and whether or not the employee is a manager.
In most business environments, IAM is a crucial service for provisioning and managing access, as well as bolstering the overall security of the IT infrastructure.

Don't Get Affected By What Others Think Of You!

2020-06-08T00:27:00.023-04:00

It is human nature to want everyone around you to like you. Be it for your talents, your intelligence or even your nature. Unfortunately, we start believing that this acceptance from others defines us. We start relying on their opinions. So much so, that we start tailoring our lives around their expectations. This makes us lose out on who we are and tends to increase stress and worry. So, let it all go and learn how to ensure your well being and establish your own identity.

Keep perspective

Another person’s opinion is always based on their thoughts and belief. Never on yours. Only you know what is best for you and your life. So yours is the only perspective that matters.

Focus on what matters

Focusing on important issues stops you from worrying about what others will think. It helps you at looking at the larger picture.

Most people don’t pay attention

People in general, pay attention to themselves only. If they are giving an opinion on your life, it is probably just in passing and they have not paid you that much thought. So you do you.

You know best

You are the one living your life and facing the consequences of your actions. Hence, you know best. Others haven’t walked your journey, learn to take a call for yourself.

Mind your own business

Stop asking what they think of you. Stop thinking of what people think about you. Especially if they are unsupportive, unhappy or too critical.

Desensitize your triggers

Being over-sensitive is always harmful. Try to control your own thoughts and don’t over-react to what people say to you. Stop overthinking and replace it with positive thoughts.

Seek constructive feedback

You should seek advice from people whom you trust. They will always give you constructive feedback because their intentions for you are pure.

Don’t try to please everyone

It is impossible to live up to everyone’s expectations. So it is simply futile trying to do it. Remember, you should live according to your likes and beliefs. People may dislike you for it, but it’s ok. You should love yourself.

Opinions are always changing

Opinions are never constant. So stop wasting time gathering everyone’s positive opinion about you.

Find a role model

You should always have a role model who you look up to and aim to be. This will stop you from becoming a people pleaser.

Life’s too short

At the end of the day, life is too short and you must not waste it trying to please everyone around you. A conscious effort must be made to stop being a people pleaser. Your opinion is the only one that matters.

All the best : )

Are you wishing to control your Anger?

2020-05-31T20:52:00.005-04:00

Have you ever figured out why you get angry?

Have you ever realized what is it that causes you to get angry?

When something you want doesn't happen,that is what makes you angry.

So you have this urge,' THIS MUST HAPPEN'.

When it doesn't happen, you get angry.

Now, remember, This universe is not for the fulfilment of your desires.

Are you the centre of the universe?

Is the whole world rotating around you?

Then why should your desires be fulfilled all the time?

It doesn't have to be fulfilled, right?

Always keep two possibilities in mind-

'My wish may be fulfilled, may not be fulfilled'.

If your wish is fulfilled, you will be happy.

You should learn to be happy from now on even if your wish isn't fulfilled.

Why should you be happy if your wish isn't fulfilled?

Because you got another chance!

Life is about only the perspectives which we see.

In this way, when you make peace with both sides, you don't get angry.

You should release this intense urge-'THIS MUST HAPPEN'.Let your mind be free.

You have done everything well, gave your best shot. Then why the need for urge?

Even if you fail, your experience never makes you fail the next time.

To conclude in short,

'Situation will not be in your control all the time, but your own state of mind will be in your control if you wish to control it irrespective of the situation.'

Now ask yourself this question, If my mind is in my control, then I will get happiness only if I wish to be happy, I will get jealousy only if I wish to be jealous, I will get anger only if I wish to be angry.

Being Stable in Difficult Times

2020-05-29T07:35:00.007-04:00

In this modern era, we have medicines for almost all diseases. Yet, illnesses are rapidly increasing. Why?

Because complications are not in the body, complications are in the mind.

Complications first get created in the mind and then those complications occur in the body. If complications in the mind are removed, complications in the body will be easy to remove.

Let me drive you into this topic with a suitable example.

Suppose your close friend came near you and said that he wants to commit suicide because he is unable to get good grades. What will you do?

Will you allow him to suicide?

No, right?

You will convince him by saying that 'That's not the correct decision, You should work even harder, Don't take negativity into your mind', right?

Now just stop for a second and think 'Why can't we convince ourselves to be stable in difficult times?'

If we could give inspiration and courage to our loved ones, why can't we inspire our own mind in difficult times?

That's where the role of thoughts comes into play.

Big challenges occur occasionally in our life. But our thought process gets affected during small challenges which we face daily.

If we are unable to think aright thought at the right moment during those small challenges, those thoughts which you think will be part of your personality soon.

That's why elders say that - 'THINK BEFORE YOU THINK'.

When you fail to think in the right way during those small challenges,you will obviously fail during big challenges that come your way.

Here is my post about achieving the right thought process if you haven't seen it yet-

https://sairohithkaranam.blogspot.com/2020/05/how-to-achieve-right-thought-process.html

Always keep in mind that "Situation is not in your control but your own state of mind is in your control."

"It's only about our inner conversation which makes us feel either happy or depressed irrespective of the situation."

It's not possible to master this kind of right mindset so easily as it requires constant hard work and self-control.

But once you achieve this kind of mindset, your mind will be stable irrespective of the situation.

Let's take a 1-week challenge. Whenever a thought comes into your mind which makes you feel uncomfortable or disturbed, try to observe those thoughts carefully which are running in your mind.

Also,try shifting your thoughts so that your mind shifts from disturbance to calmness.

Personal Recommendation:

This suggestion is given by my parents to me for my better mental health. I hope it works for you.

'When you wake up in the morning, charge your mind in such a way that the thoughts which you will think all the day should be pure and powerful'.

In one word, it is nothing but MEDITATION.

References: BK Shivani Videos