In this lesson, we are going to to talk about an important part of computing that makes working in IT supporter a little easier. Actually, it makes things a lot easier for just about anyone. Picture this, you're on your way to an important meeting. You've been rehearsing for this presentation all week and now you're ready to show the big wigs what you've got. But wait, the slide deck, where is it? It's not on your laptop. Where could it be? It turns out you forgot your only copy on your desktop at home, it's too late now to turn around and get it so you sit there dreading the inevitable. But wait a minute, suddenly you remember that you have a remote connection set up from your laptop to your desktop. You use this connection to log into your computer at home. And just as if you are sitting at home, you're able to grab the file from your desktop and copy it to your laptop. You then proceed to give one amazing presentation. Consider another scenario. You bought a computer at a store and you're having a lot of issues with it. The store has a computer help desk that can help you with the issues, but it's after hours and the store's closed. You really need to get your computer issue fixed. So what are your options? Fortunately, the store provides 24/7 tech support online. Now instead of worrying until the physical store is open again, you can reach a tech online and have them help you with your issue through a remote connection. Remote connection makes working in an IT Support role much easier since it allows us to manage multiple machines from anywhere in the world. In this lesson, we're going to learn about remote connection. You've actually already been using it throughout this course. We've been using the Chrome remote desktop connection to access our Windows Qwiklabs, along with SSH, or secure shell, to securely log in to our Linux Qwiklabs. But we're going to dig a little deeper in this lesson and talk about how remote connection works and the different methods to connect remotely to a machine. SSH or secure shell is a protocol implemented by other programs to securely access one computer from another. In the Qwiklabs exercises, you've been using the Google Cloud console SSH client to access the Linux VM instances. To use SSH, you need to have an SSH client installed on the computer you're connecting from, along with an SSH server on the computer you're trying to connect to. Keep in mind, that when we say SSH server, we don't mean another physical machine that serves data. An SSH server is just software. On the remote machine, the SSH server is running as a background process. It constantly checks if a client's trying to connect to it, then will authenticate it's request. The most popular program to use SSH with in Linux is the OpenSSH program. We'll be using it in this lesson, but we wont talk about how to install it just yet. We'll circle back to that in the next course, System Administration and IT Infrastructure Services. The same goes for Windows. We'll talk about how to use SSH from a Windows machine using the popular open source program PuTTY. For now, let's just talk about what happens when you use SSH. We're going to show you an example of SSHing into a remote machine. We already have an SSH client installed on this machine, but don't worry, we'll talk about the different SSH clients and installing them on the next course of the program, System Administration IT Infrastructure Services. So first things first, to log in to a remote machine we have to have an account on that computer. We also need the host name or IP address of that computer. Let's test this. So, ssh cindy@ IP address. We get this message. The authenticity of hosts, and then the IP address, can't be established. This message is just saying we've never connected to this machine before, and our SSH client can't really verify we're connecting to a machine we want to connect to. But we can verify this is the right machine. So let's just go ahead and type yes. Now, this host gets saved to the computer as a known host, so we won't get this message again when we try to log into it. Okay, now that we're connected through SSH, any of the text commands that we type are sent securely to the SSH server. From here, you can even launch an application that'll let you see a GUI instead of working directly in the shell. You can read more about how to do that in the supplemental reading. We can connect SSH using passwords, as you saw earlier. This way of authenticating to a remote machine is pretty standard, but it's not super secure. The alternative is using an SSH authentication key. SSH keys come in a set of two keys, called private and public keys. You can think of them as actual physical keys to a special safe. You can use one key to lock to safe, but it won't unlock it. The other key can then only unlock the safe, but not lock it. That's basically how public and private keys work. You can lock something with a public key, but you can only unlock it with a private key, and vice versa. This ensures that whatever's in the safe is available to only those with the public and private keys. You'll learn about the technical details of public and private keys in our IT security course. Don't worry if this doesn't make sense right now, it will. And that's basically how SSH works. Not too scary, right? Another way that you can connect securely to a remote machine is through a VPN. A VPN is a virtual private network. It allows you to connect to a private network, like your work network, over the Internet. Think of it as a more sophisticated SSH with a lot more set up. It allows you to access resources, like shared file servers and network devices, as if you are connected to your work network. Spoiler alert, we'll also touch upon the technical details behind VPN in the IT security course. We've covered a lot about remote connections and how they work. We'll take more about the popular remote connections programs for Windows and Linux and how to set them up in the system administration course.
