Monitor Bandwidth In Real Time

Today we’re going to have a fun article, an easy enough article, where we simply talk about one way to monitor bandwidth in real time. This is not something you’re normally going to do unless you’re in an unusual situation. It’s still something fun and easy, so why not cover it?

This might be useful if you want to monitor bandwidth at an edge system. Let’s say you have a public-facing server and you’re not behind a router that gives you this information in a fancy widget or whatnot and you want to monitor the bandwidth in real time. Well, you can do that. In fact, there are all sorts of tools that will let you do this. Heck, I think I may have even shared some of this type of stuff in the past.

Maybe take a gander at some of the following articles:

Monitor Bandwidth With nload
‘vnStat’ A Tool For Monitoring Your Bandwidth Usage
Visualize Your Network Traffic With ‘darkstat’

(There are more, just search the site for ‘bandwidth’ – which is how I came up with those links. I wasn’t picky, I just picked the first few that looked like they might interest people and be similar to this one.)

As I mentioned, it’s easy to monitor your bandwidth. It’s easy to monitor your bandwidth in real time. There are countless options and applications for this, so today we’re just going to cover one more option from the myriad options available to you as a Linux user.

Today’s article will be about ‘cbm’… Trust me, it’s easy. It’s very easy!

What Is This cbm?

Well, cbm stands for Color Bandwidth Monitor and it’s not a new application. In fact, the GitHub page indicates that it hasn’t been updated in a while. That’s not necessarily a bad thing, as it could mean that it’s just feature complete and in need of nothing.

I’ve only checked on Ubuntu (technically Lubuntu) and Mint, but cbm is in the default repositories. I’m a bit of a slacker, so I haven’t checked elsewhere, but it’s probably in their default repositories too. It’s just a tiny application with a very specific purpose. Those are the kinds of apps that make it into default repositories.

If you check the man page, you’ll see that cbm defines itself simply as:

cbm – display in real time the network traffic speed

Supposing you’re using Ubuntu (or Debian, or Mint, or any other distro with those repositories and using the apt package manager) it’d be easy enough to install.

You’d simply install cbm with the following command:

So, let’s pretend you’ve already got that cbm application installed…

Monitor Bandwidth In Real Time:

So, we’ll assume you’ve already installed cbm but you’re still going to need an open terminal to use cbm. Funny how that works! You know what, I’m just going to assume you’ve opened a terminal to install the application and skip that whole cookie-cutter silliness.

Well, now that you have cbm installed and you’ve run cbm in the terminal (which is your only option – I did mention this was absurdly simple), you’ll see an output similar to this:

cbm letting you monitor bandwidth in real time
It’s not polite to laugh at another man’s paltry bandwidth! Be polite!

Yes, yes I work just fine within these bandwidth constraints… Mostly…

As you can see, it shows each network interface.

How To: Show Your Network Interfaces

You can see that it shows how much data you receive, how much data you transmit, and the total. I did not let it run all that long for the screenshot, as that’s not necessary.

That’s pretty much it. There are few options and that’s a good thing.

You can press the + or – to change the refresh rate.

You can press B to change from bits to bytes.

When you’re done monitoring your bandwidth in real time, press Q to exit the application.

That’s it. That’s all you need to know. It’s a very purpose-built application. There aren’t a bunch of frills and options. This is one of those tools that does exactly what it says on the tin and nothing else. If you want to monitor bandwidth in real time, this is one way to do so.

Closure:

See? I told you this would be a nice and simple article. It’s easy to follow and easy to learn. There isn’t a whole lot to it. You can monitor bandwidth in real time with all sorts of tools, but this might be one of the easiest. The program doesn’t need to be updated. It doesn’t need additional bells and whistles.

Sorry for not checking on alternative distros. That takes a while and I have limited time to write these things. If you use other distros, you can help by leaving a comment to indicate if it is in your default repos or not. You can even go so far as showing how to install cbm. It won’t hurt and you don’t even have to use real information!

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Remove Unused Kernels From RHEL

Today’s article is only going to apply to some of you, specifically those who use RHEL and want to remove unused kernels from RHEL. That’s a pretty narrow subset of people, but it’s worth knowing this information if you’re a RHEL user.

Red Hat is one of the oldest Linux distributions out there. Along the way, they’ve turned into an ‘enterprise’ (business class) distro. They’ve made some strange strategic decisions lately, but I’m not going to get into that in this article.

As an enterprise distro, it is not entirely free (as in cost in dollars). They are a distro that has a great deal of support for long periods. They’re meant to be stable and ideal for business use. You’re expected to pay for RHEL – sort of.

RHEL has a free version if you sign up as a developer. You can learn about the RHEL developer program at this link. I thought it was free for a few devices, but it looks like I might be wrong and that it may be more than that. From the linked page:

An entitlement to register 16 physical or virtual nodes running Red Hat Enterprise Linux.

So, that’s more than three – but you’re not going to get support. If you want to go this route, you’re expected to support yourself. Fortunately, RHEL has extensive documentation and your dev subscription will get you access to any of that documentation that’s behind a paywall. Or, at least that’s my experience.

I don’t do enough with RHEL!

Linux Kernels:

I’ve explained what the kernel is before. Linux is just the kernel. We add stuff to the kernel to make an operating system. We then add more stuff to make it a specialized operating system – such as a desktop operating system, like the readers of this site use.

Along the way, as you update and upgrade, you’ll add new kernels. These are not necessarily removed by default. They can take up quite a bit of space and you might be paying for that space (especially if you’re using RHEL as a server somewhere). So, removing the oldest kernels is just good housekeeping.

That’s all we’re doing in this article. I suppose it’d probably also work for CentOS but I don’t pay any attention to that distro these days. It’s not that I’m angry or annoyed with RHEL’s decisions, it’s that I only care for things with long-term support. I’m old and changes scare me!

We’re just going to clean up any old kernels, probably while keeping the 2 most recent kernels, to keep things nice and orderly. This isn’t something you technically have to do. You can keep all the kernels you want. But, if you want to remove unused kernels from RHEL this might be the article for you!

Remove Unused Kernels From RHEL:

Now, if you’re using RHEL as a server then you’re already connected via SSH (probably) and already have a terminal open. If you’re using RHEL as a desktop OS, you will need to open a terminal. You can just press CTRL + ALT + T and your terminal will pop open.

With your terminal open, you first need to install yum-utils. That’s nice and easy, just use this command:

(You’ll need elevated permissions unless you’re logged in as root.)

Next, run the following command to see how many kernels you have installed:

If you have more than two kernels installed, you can run this command:

You can adjust that command if you’d like. That particular command will keep the kernel you are currently using and the previous kernel. (You can boot to older kernels via GRUB if you want. That article is actually about recovery mode on Ubuntu, but the pictures should clue you in until I write an article just for this purpose.)

If you use a --count= of 1 or 0, it will remove every kernel except the one in use, it will not remove the kernel that’s in use.

That’s all you have to do. There’s nothing more to it. The command will automatically remove older kernels at the level you decided. You can keep the most recent three kernels, four kernels, or however many kernels you want. It’s not terribly complex.

Closure:

I don’t do a whole lot of RHEL articles, but it’s nice to at least write one here and there. If you’ve got extra kernels, you now know how to remove unused kernels from RHEL. It’s a pretty easy task and something even a new user can handle. If you’re a new user, go for it! It won’t break anything – in and of itself. (I’d highly recommend keeping the current kernel and the most recent kernel, just in case.)

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Let’s Make The rm Command Even Safer

Today’s article is one I don’t expect most folks to follow, but it’ll be a fun way to make the rm command even safer. If this article sounds familiar, then you remember a recent article. Well, this article takes it a step further and we’re making the rm command even safer!

See, in the last article you learned how to:

Let’s Make The rm Command A Little Safer

Despite the naysayers not seeing the value, that article will help you make the rm command a little safer. It adds a sanity check. If you followed the directions, you’d get the chance to tell the rm command to ‘never mind’ and to ignore your command prompt. This can stop you from removing files accidentally.

While I wrote that article, I already had this one planned, but didn’t want to publish the two back-to-back. I try to mix things up a little.

NOTE: If you followed the directions in the first article and decide you’d rather go this route, you’ll have to undo the actions you took. These two things can not work together at the same time. It’s a one or the other kind of thing.

What will we be doing in this article?

Well, simply put, we’re going to use an alias like we did in the previous article about making the rm command safer – except we’re also going to define a function and alias the rm command to that function instead.

What will that function do? Well, in short, it will take the results of the rm command and stick the files in your trash (recycle) bin. It makes the rm command work similarly to your regular delete (depending on the distro). Instead of deleting files, it happily sends them to the trash bin instead. So, if you screw up you can restore the files nice and easily with your GUI (by going into the trash bin and restoring the files, of course).

This is a bit more complicated. That’s why I went with the previous rm command modifications earlier. This still isn’t all that complicated. I realize this is something new to most of my readers, so I’ll make it as clear as humanly possible. (Wish me luck!)

In the previous article, we made the rm command a little safer. This time around, we’re going to try to …

Make The rm Command Even Safer:

Yes, you’ll need an open terminal. You can likely press CTRL + ALT + T and your default terminal should open. Otherwise, open it from your application menu.

These directions will assume you’re using Nano. If you are not using Nano, please adjust the directions to suit your text editor of choice.

With your terminal open, I want you to enter the following command:

Then, and this may be confusing, I want you to copy and paste all of the following text at the very bottom of that file:

Next, you need to save the file. As we’re using Nano, you save the file by pressing CTRL + X, then Y, and then ENTER.

Next, you need to tell your system to reload the ~/.bashrc file. You can log out and back in, you can close all the terminals and open a new one, or you can simply type the following:

NOTE: In the second code block you’ll see ~/.local/share/Trash/files. This should be the correct path to your trash bin. You should verify this and change the path accordingly. This directory ONLY exists if you’ve previously moved something to the trash. You’ll need to create a file and move it to the trash or you’ll have to make the directory manually.

Testing This New rm Command:

Leave your terminal open and open your GUI file editor. With your GUI file editor open, navigate to ~/.local/share/Trash/files.  You may not see it by default, so change your GUI file manager’s options to show hidden files and directories. (You can often use CTRL + H to show hidden files.)

Now that you’ve navigated to the directory with your GUI file manager, return to your terminal emulator. Once there, type the following:

You can then run ls to ensure the file foo.txt exists. Next, you’re going to delete it with the rm command:

Again, you can then run ls to ensure the foo.txt file has disappeared. It should certainly be gone from the directory you were in and removed by the rm command.

Except, it wasn’t!

Go back to your GUI file manager and (you might need to refresh it, depending on the file manager) check the list of files. Sure enough, you should see a foo.txt in the trash bin. It’ll remain there until you restore it or until you empty the trash.

Pretty neat, huh? 

Closure:

The first article made the rm command safer. This article will help you make the rm command even safer! You can’t do both (easily), but you can do one or the other. I mean, I’m sure it’s possible but I’ve never thought of a way to do so. I haven’t tried to think of a way to do so. So, there’s that…

If you follow this article, your rm command will send the files deleted by rm to the trash bin. If you follow the first article, you get the chance to view your command’s outcome and decide to back out of the file removal process. You can pick whichever one works best for you.

You can also completely ignore these things and just keep on doing what you have been doing. This being Linux, you can make all sorts of choices – including this one. Though, I think it was Rush who said, “If you choose not to decide you still have made a choice.”

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Let’s Talk About The Deep Web vs Dark Web

Today’s article is going to be quite different than a normal article, as I discuss the differences between the Deep Web vs Dark Web. The reason I wrote this article is because I was having an online conversation with someone and they didn’t know the difference. In fact, they weren’t familiar with either of the terms but used them both for the same thing.

So, sit back and relax. This article might be informative if you’re not already aware of these words and what they mean. If you’re already familiar with these words, you can skip this article – or scroll to the comment section to add your thoughts on the matter.

There’s a subset of people who would think these names are interchangeable. They share some similarities but they’re decidedly different. I’ll do my best to explain the difference between the deep web and the dark web. It sounds like a good article to write.

The Public Web:

Before we can talk about either of those two things, we should probably talk about the public web. That’s just the tip of the iceberg, but the public web is the sites you visit while you’re online. These are sites that are open to anyone. They’re sites you can find with your normal search engine.

For example, this site is a part of the public web. You can search for it and find results. It’s possible to visit the site directly. You can interact with the site, browsing around as you see fit.

Everyone’s familiar with the public web. This is all the major sites, the sites that get the vast majority of traffic. They’re the places we hang out, meet with friends and family, and exchange information. They’re just your typical websites.

All of these things have one thing in common. You connect to your ISP to access them – but they use vastly different technology underneath. The public web uses just plain web servers, a markup language, and is delivered via HTTP or HTTPS. You know, the sites you regularly visit.

The Deep Web:

The Deep Web is something we all encounter. Simply put, the Deep Web is stuff that doesn’t get indexed by public search engines. This is also true of the Dark Web, but we’ll discuss that in a minute.

For example, your banking is technically in the Deep Web. I mean, ideally, it is. It’s a site with data that’s not indexed by search engines. This is true for IRC (Internet Relay Chat), SMTP/POP3 (email), IMAP, (more email), and even the old gopher network that still exists.

This Deep Web also includes stuff behind a paywall. This could be a private stock exchange portal or it could be the archives at your favorite newspaper. This also includes things like private forums. If a public forum has a private section then that section would technically fall under the title of Deep Web.

There’s nothing wrong with the Deep Web. There’s nothing inherently wrong with any of these categories. They are what they are. I have a private forum and no you can’t join it. It’s for friends and family. As such, it’s a part of the Deep Web.

The Dark Web:

Now, the Dark Web is a whole different animal. The Dark Web requires different protocols and special software to access it. It will also include encryption and will (generally speaking) be poorly indexed (if at all) by public search engines.

The Dark Web includes various P2P connections. A few examples would be Tor, I2P, or even Freenet. While this data does transmit over the internet, it uses various protocols that are unlike those used for the public web. Encryption is enforced and a stated goal for many of these services is anonymity.

It is NOT illegal (at least not in my country) to access the Dark Web. In and of itself, accessing the Dark Web violates zero laws. Just like you can access IMAP for your email, you can access the Dark Web.

HOWEVER…

The Dark Web is where you’ll find a concentration of illegal activities, from drug sales to firearm sales to worse. Performing those illegal activities is still very much illegal. The level of security you’d have to maintain at all times is so burdensome that people are caught every day for performing illegal activities on the Dark Web.

Yes, you can find illegal activities on the public web. You’ll find a concentration of them on the Dark Web.

So, Deep Web vs Dark Web:

So, accessing the Deep Web is perfectly normal. That behavior doesn’t stand out at all. Just accessing your bank means you’re accessing the deep web – and that’s a good thing. You don’t want that banking information to be available with a simple Google search.

Accessing the Dark Web isn’t illegal, but that’s where a lot of illegal activities take place. You’re unlikely (I’m sure some jurisdictions make this illegal) to attract any attention unless you’re dumb enough to try using it for illegal activities. Before you think you’re smart and will keep your “OPSEC” squared away, every other person thought the same thing before the law was knocking on their door.

So, when it comes to Deep Web vs Dark Web, you might as well know the difference in terms and what those terms mean. 

Closure:

Yes, this could have been so much more technical. The idea for the article stemmed from a conversation and I don’t want to be all that technical. This is meant to be a light discussion about the Deep Web vs Dark Web. Nothing more. Nothing less…

Thanks for reading! If you want to help, or if the site has helped you, you can donate, register to help, write an article, or buy inexpensive hosting to start your site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

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