From the course: Career Essentials in System Administration by Microsoft and LinkedIn

Static and dynamic routing

From the course: Career Essentials in System Administration by Microsoft and LinkedIn

Static and dynamic routing

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- [Instructor] Static and dynamic routing allows us to set up routes to other networks whether they're inside or outside our local area network. On the left hand side, we see a Windows computer and on the right hand side, we see a Cisco firewall and the commands to make this work are slightly different based on the type of operating system you're using, for example on a Macintosh. Linux, or Unix computer you're going to see even different syntax. Let's start with the windows computer on the left. I'm going to type in route add, and that starts us out. Now, if I put in a forward slash P it's going to be persistent meaning that even after I restart my computer that route is going to stick, otherwise it will disappear after a reboot. Now I need to put in my destination subnet and put in my subnet mask, in this case, I have to type in the word mask followed by what the subnet mask is. Then I have to put in my gateway out to that subnet and it has to be an IP address on my current subnet, which it is, I'm in the 21 network. And we were successful in setting up that route. What this is saying is that there's a router or a layer three switch at that 21.1 IP address that's going to get me to that 22 subnet. Now on the right hand side, if this were a Cisco switch or firewall, then my routing state would be this. I'd start out with IP route followed by the destination subnet and I don't have to type the word mask, I can just type in the mask and then followed by whatever IP address is the gateway and I'll just make up an IP address again. And what this would do is it would get us to the 22 network and we're pretending that there's a router at the 21.200, it could also be a layer three switch that does routing as well. Now, if I wanted to do this on a Cisco ASA firewall then my syntax has to be a little different. So now we'll type in the command route inside followed by the destination subnet and then the subnet mask, and then the gateway. So this assumes the same thing, that we have a router or layer three switch at .200 which is the gateway to the 22 network. Now it says route inside, what inside means is that the name of the network interface is inside. You can have an inside interface and an outside interface which are the default names you get when you purchase a Cisco ASA firewall, you can change the names if you like and you can have more interfaces with other names as well. Back on the Windows side, if I want to delete this particular routing statement then I can type in route and then type in delete followed by the destination subnet and that's all I have to type, and now it'll go away. Dynamic routing does this routing in a way that will be automatic, so I won't have to go in and add in manual routing statements for each particular route that I want to go. It will find the best path to get from my location to the destination. So on our Cisco ASA firewall or switch I'm going to type in router space rip, after I type the word version I can type in two for version two and now we're in version two for rip and rip stands for routing information protocol. Then I can add in any networks that I would like and you can add in as many different networks that you need to have routing rip to be able to discover. On a Windows computer in order to add routing information protocol for a dynamic route we have to go in and add a certain role first. So we'll go in and add in the remote access role and choose to install it. Now it's asking us what we would like to do as far as the role services, I'm going to put in both VPN and routing, we don't need the web application proxy. After this installs, we're going to see a new option in server manager under tools, once rip version two is installed and configured on the Windows server, it can communicate with the Cisco firewall or switch or any other device that uses the same dynamic routing protocol and there are multiple different protocols you can use. However, the windows server is only going to support rip. And after that happens, they're going to advertise the other subnets that they're connected to and tell each other all about it, so you no longer have to set up each route statically. So then I'll be able to get to the 22 network even without adding in static routes. Installation is complete, so now I'll go to tools and we'll see routing and remote accesses now here, and I'm going to start the wizard to enable it, by default it's turned off and that's because there's a lot of different options. So I'll right click and choose configure and enable routing and remote access and the wizard pops up. I'm going to choose the custom configuration, but there's lots of different ways that you can do this and I'll choose land routing because that makes the most sense and click finish. Once it's done, we'll click start service and this effectively turns our Windows server into a router as long as you have at least two network interface cards. I'll expand IPV4, go to the general setting and right click and choose new routing protocol. I'll choose rip version two and click okay, and now rip appears. Dynamic routing automatically finds the best route between subnets, VLANs, and devices. Static routing allows you to designate the route you would prefer the switch or router or server to take rather than having the device make that decision for you.

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