Tag: networking

How To: Change DNS Servers

Today’s article shouldn’t be all that difficult for even our newest users but is limited to those who want to change DNS servers to something other than the default. This is easy enough to do, but obscure enough to warrant an article of its own. 

First, let’s have some fun. I’m going to ask ChatGPT to tell you about DNS in just two paragraphs. So, let’s see what the AI has to say:

First, what is DNS?

DNS, or the Domain Name System, is a fundamental protocol used in computer networks to translate human-readable domain names into machine-readable IP addresses. It serves as a decentralized directory system that enables users to access websites, send emails, and perform various network activities using familiar domain names instead of numerical IP addresses. When a user enters a domain name in their web browser, the DNS resolver (typically provided by the Internet Service Provider or ISP) initiates a series of queries to locate the corresponding IP address. The resolver communicates with DNS servers, starting from the root servers, then the top-level domain servers, and finally the authoritative name servers associated with the requested domain. Through this hierarchical process, DNS ensures efficient and accurate resolution of domain names, facilitating seamless internet connectivity.

DNS operates through a distributed database system known as the DNS namespace. This namespace is organized hierarchically, with the root domain at the top, followed by top-level domains (TLDs) like .com, .org, or country-specific domains such as .us or .uk. Beneath the TLDs, there are second-level domains, and further subdivisions like subdomains. Each domain has authoritative name servers that store the IP addresses associated with the domain names they manage. DNS resolution occurs through recursive queries, where the resolver traverses the DNS hierarchy to find the authoritative name servers responsible for the domain. Once the IP address is obtained, the resolver caches it for future use, reducing the need for repetitive queries. DNS plays a crucial role in the functioning of the internet by providing a scalable and efficient method for translating domain names to IP addresses, enabling seamless communication and accessibility across the network.

Wow! That’s pretty accurate. I’d have just resorted to describing DNS as the telephone book of the internet. You look up the name you want to reach and DNS tells you the number. In this case, the number is the IP address.

All in all, I’d say ChatGPT did a pretty fine job.

Change DNS Servers:

There are a variety of reasons why someone would want to change DNS servers to something else. They may get updated more quickly, weed out junk domains, or even remove ads and things like that. Maybe you want to weed out inappropriate material because you have children. Perhaps you have some custom configurations needed to traverse your complex local network. There are all sorts of reasons why you might want to change DNS servers.

See, as alluded to above, it’s perfectly possible to run your own DNS server (see Pi-hole for one such example). You can also use DNS servers provided by various third parties. For example, CloudFlare and Google offer their own DNS servers that are free for you to use. There are other choices, but this isn’t an encyclopedia writ large, so I’m going to just include those two. You can use your favorite search engine to find more.

So, let’s say you don’t like using a DNS server provided by your ISP. Perhaps you do this because of privacy issues, though you can look into DNS over HTTPS if you’d like. Perhaps you just don’t find them updated quickly enough or you’ve found they contain errors. (They do sometimes have issues and have even been known to be exploited in the past.)

NOTE: We’ll be using ‘nano‘ for this exercise. We’ll also default to Google’s public DNS servers, but you can substitute with whatever you find available.

Well, the first step you’re going to take is opening your terminal. You can do that by just pressing CTRL + ALT + T. In most distros, that will open the default terminal emulator. If your distro doesn’t do so, start mucking about with the keybindings until it does!

The file we’ll be editing doesn’t actually exist on most distros. That’s not a problem, because we’ll be making that file with nano. With your terminal open, enter the following command:

That should be a perfectly blank file and you’ll want to enter the following (again, using Google’s public DNS servers) to change DNS servers:

Then, you’ll save the file with Nano. That’s pretty easy. To save this new resolv.conf file with nano, you just press CTRL + X, then Y, and then ENTER.

Next, you’ll need to reboot. I know this will pain some of you, but I’ve yet to have a sure way to effect these changes other than rebooting. So, you’ve gotta do that. Try this command:

Now that you’ve managed to change DNS servers, you should be able to browse around much as you normally would. Remember, the people in charge of the DNS servers are the ones that decide where you go when you enter an address into the address bar and smash that enter button.

Be sure to use a company you trust to provide those services and be sure to verify your internet is still working properly. If it’s not working, you can remove the file and reboot or you can edit it again and try rebooting again. It shouldn’t be a problem in reality, this isn’t anything all that complicated.

Closure:

So, there you have it. It’s yet another article. This time around we discussed how to change DNS servers – along with some reasons as to why you might want to. If you have a spare bit of hardware kicking about, you can make your own DNS server and point to that with the internal addresses you’d be using. It’s nothing too painful and I think even beginning Linux users can follow along easily enough.

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.

Smash a button!
[Total: 1 Average: 5]

Show A Specific Networking Interface

Today, I’m just going to write about a simple task, how to show a specific networking interface. This seems like a good short article.  It won’t be too complicated and it’s suitable for a beginner. Read on, if you are interested in learning how to get the information for just a specific networking interface.

It’s also suitable for most people, as most people only need information from a single, specific networking interface. Most folks reading this site are home users of Linux and it’s quite likely that they’re only connecting over one network interface, be it ethernet or wifi. Frequently, you only need to show a specific networking interface when gathering information from the terminal.

If you’re still using ‘ifconfig’ you can close this tab immediately. The tool is deprecated and we’ll just be using the ‘ip’ command. Odds are good that your distro has already moved away and is using the ip command. If your distro hasn’t done so, it should be noted that the process of deprecating ‘net-tools’ (from which you get ifconfig) started in like 2001. You may still have the legacy tool, but we won’t be covering it.

Anyhow…

That’s a long intro for something this short…

Show A Specific Networking Interface:

This is yet another article that requires an open terminal. So, crack open your favorite terminal. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

With your terminal open, you can run the following command:

You can even run:

Or, you can get that information for a specific networking interface. To do so, we just use the first command, like so:

For example, if your NIC is called ‘eth0’, the command would look like this:

The output from that command will be just the information about that specific networking interface. You won’t have the clutter of the first two commands listed and it will only show the device you specify. If you’ve only got one network interface in use, you can just store the final command in your memory for when you need to check some of your networking information.

Closure:

See? I told you that it’d be quick and easy. Not all of these articles need to be long and complicated. Besides, my 2-year anniversary is coming up, meaning a short and simple article is a good thing. I don’t want to burn out or anything, not at this stage of the game.

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.

Smash a button!
[Total: 3 Average: 5]

Another Way To Find A Website’s IP Address

Today’s article will just be a fun one, where we cover yet another way to find a website’s IP address. It’s mostly for fun but it’ll also introduce you to another tool for your terminal-toolbox. After all, there’s almost always more than one way to do things in Linux, including finding a website’s IP address.

So, today we’ll be using a tool I don’t think I’ve covered before. While we have done the website IP address thing before, I don’t see the ‘nslookup’ tool anywhere in the site’s history. We might as well, as I could use a quick and easy article today, as I’ve been busy making a delicious ham.

Odds are good that you have nslookup installed by default. If you don’t, it’ll be easy enough to install with your package manager. If you check the man page, you’ll find the tool describes itself as:

nslookup – query Internet name servers interactively

And, yeah, that’s what we’ll do with nslookup. We will use it to do what it’s designed to do. We do that often around here and, of course, we’ll be doing all this in the terminal. I’m sure there’s some GUI tool you could use, but every Linux distro that I know of comes with a terminal. It just makes good sense for most articles!

Well, that’s enough blathering about what you’re going to read…

Find A Website’s IP Address:

As the intro mentioned, we’ll be doing this in the terminal. So… Open a terminal of your choosing. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T.

With your terminal now open, the syntax is simple:

You’ll often get more than one IP address in the answer, but that’s because sites will often respond on more than one IP address. For example (and considering that I’m behind a CDN), this site would look like this:

it's easy to find a website's IP address
See? It’ll answer on an IPv4 or an IPv6 address at this time. Pretty easy, huh?

Go ahead and try using nslookup to find the IP addresses of your favorite sites. There’s no harm in doing so and it can be a useful bit of information – though usually, that’s more useful for the site’s admin. Still, it can be a handy bit of information.

Closure:

There! See? Another quick and easy article. This time, we’ve shown another way to find a website’s IP address. It’s not complicated and the output is easy enough to process. Enjoy the tool and have fun with it.

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.

Smash a button!
[Total: 4 Average: 5]

A Couple More Ways To Find Your Network Interfaces

Today’s article is mostly just for fun, as we examine a couple more ways to find your network interfaces! I’ve shown you a variety of ways at this point, but this is Linux. If you just want to have some fun finding your network interfaces, read on – ’cause this article is meant for those who like to travel a different path!

One of the things that make Linux so awesome is the myriad choices we have. There are so many different ways to accomplish the same goal. In fact, we sometimes get defensive about ‘our way’ of accomplishing things. It can make for some amusing (and sometimes a bit heated) discussions. 

Anyhow, I’ve covered this before. I’ve even covered it recently, which is why this is still fresh in my memory. You can start with this article if you want:

How To: Show Your Network Interfaces

Just to touch on it, a network interface is a device that your computer uses to communicate over the network. In most folks’ cases, you’ll locally use your network interface to connect to the Internet, perhaps first to your router or modem. These networking devices have names.

It’s important to be able to point to a specific networking interface, which is why they have names. If you want to issue commands, you want to send them to the right networking interface. If you want to monitor a connection, you need to know the correct name for the network interface.

So, these network interfaces have names. These names should be unique in your system, meaning you shouldn’t have more than one device per name. The names should not be shared among the devices and each working networking interface should have a name of its own.

If you want to know the network interface names, this article’s for you…

Find Your Network Interfaces Continued:

This article requires an open terminal, like many other articles on this site. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

With your terminal now open, we’re going to show you a couple of new ways to find your network interfaces. It’ll be fun!

For starters, and probably one I should have already covered, we’ll use a command we’ve covered here and here. We’ll use the ‘netstat’ command, and the ‘netstat’ command you need to find your network interfaces is simply:

(If you don’t have ‘netstat’ available, install the ‘net-tools’ package from your distro’s repositories. It’s almost certainly available.) The output is nice and clear and will show you the names of your network interfaces.

The next command we’ll use is one we’ve used many times before. It’s just a two-letter command, so trying to search for it (on this site) is neigh on impossible – but you can be certain that we’ve used it before. (We’ve at least covered sorting and formatting the output from the ‘ls’ command.)

Anyhow, the command we’ll use to list the network interfaces is pretty simple, it’s just this simple command:

That ‘ls’ command should spit out a list of your network interfaces all nice and easy. If there’s going to be one command that’ll work on any system, it might be this one.

Speaking of which, as this is Linux, there are all sorts of ways to accomplish goals. Because of this, that also means they’ll not always work on every system. You may need to try multiple commands to get the output you’re after – but both of today’s commands should result in you getting the names of your network interfaces (even if you have to install ‘net-tools’ to do so).

Closure:

There you have it, another easy article. Ugh… I do wish I was feeling a bit more up to snuff. Meh… At least I’m writing and writing this sort of stuff. In this case, it’s another article that’ll show you how to find your network interfaces. It’s information worth having. They’re tools that will go well in your growing toolkit of Linux tools.

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 own site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

Smash a button!
[Total: 8 Average: 4.9]

Visualize Your Network Traffic With ‘darkstat’

Today’s article is a fun one, an article where you’ll learn how to visualize your traffic with darkstat. It’s a fun little tool that lets you graphically visualize your network traffic in your browser. While it’s likely more of an enterprise-level tool, there’s no reason you can’t use it as a home user.

So, if you’d like to learn how to visualize your traffic with ‘darkstat‘, read on and I’ll do my best to explain it. 

There’s a lot to the tool, but darkstat defines itself in the man page as:

darkstat – network statistics gatherer

We’ll only be using darkstat to visualize your network traffic in the browser, but there are quite a few options available. You’ll want to check the man page after you’ve got darkstat installed and have learned its basic usage.

I’ve previously covered tools like VNstat, which lets you monitor your bandwidth usage. You can even helpfully draw some graphs with the tool. This is quite different. You’ll see…

Visualize Your Network Traffic With ‘darkstat’:

This article requires an open terminal, like many other articles on this site. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

First, you need to install darkstat. It should be in your default repositories for many of you. To save time, I’ll show you how to install it in Debian/Ubuntu-based distros. Just adjust the command to suit your system’s package manager:

With darkstat now installed, you need to start it – so that it monitors your network traffic. To do that, you’ll need to know the name of your network interfaces. It just so happens that I wrote that article last time:

How To: Show Your Network Interfaces

Armed with that data, you want to start darkstat and the format is:

So, for example, you might end up with one of the following commands:

Or maybe this type of command for a wireless connection:

After running that command, you’ll then want to open the following URL with your preferred browser:

http://0.0.0.0:<port_number>

If you used the port above, you’d connect to:

http://0.0.0.0:8080

The results should look something like this:

darkstat in operation
The output of the graph should be easy enough to understand.

You can also opt to see the hosts, those servers you’ve connected to, by simply clicking on the ‘hosts’ link. That’d look something like:

 

darkstat in action, showing the hosts
As you can see, this one shows the hosts you’ve connected to.

The darkstar application will run quietly in the background. It’ll keep running until you tell it not to. One way to kill darkstat would be:

As I mentioned above, darkstat has a number of different options. There’s a bunch more to it, but this is about all your regular user will need to visualize their network traffic. Of course, run man darkstat to view those options.

Closure:

There you go. You have another article, this one less short than the recent articles. I am not well, but I presume I will be. In the mean time, we’ll continue to have articles for as long as I’m able. This time, we learned about how you can visualize your traffic with darkstat. Who knows what the next article will be about.

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 own site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

Smash a button!
[Total: 13 Average: 5]
Subscribe To Our Newsletter
Get notified when new articles are published! It's free and I won't send you any spam.
.
Linux Tips
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.