Network Hardware Issues

Name: Network Hardware Issues
Author: Matthew Mercaldi

Learn about physical network issues

Preview the first lesson free — get full access to all 3 lessons.

Course: On-Demand

Hello, my name is Math Merkaldy, and these lessons you will learn about route path, address resolution protocol, and network interface cards. For route path, I currently have a lab set up, in which we currently have three locations represented by a router, router one, router two, router three. Uh, this is a hub and spoke model, in which router three is a hub, and you can tell it's a hub because it's directly connected to the internet here. Router one and router two are gonna be using the resources of router three to connect to the internet. We can see here, and we see that first off, they're connected to each other via OSPF. OSPF is a dynamic routing protocol. So instead of me doing static routes everywhere, I just do OSPF, and it does all the routing for me. Now here, we see an issue, and this comes up all the time when doing dynamic routing, is we have the 1 9 2 1 6 8 5 dot 0 network. Uh, there's equal costs routing going on here, which means that right now, in order to get to 1 9 2 1 6 8 5 network, is using 1 0 0 2 2, but for any reason at all, it could be using the other hop of 10 0 1 2. We don't want that, right? Any number of reasons could actually cause uh, this to flip over, and it's not good policy to have something like this. This could lead to a whole slew of issues, especially, since this is a point to point, and technically, this is also a failover, as well. So, you know, maybe we uh, have monitoring software here in which we wanna monitor, you know, 1 9 2 1 6 8 5 dot 1, and we wanna make sure that we can access everything appropriately here. There are a couple ways we can go about this to make sure that we get the appropriate route paths. Now, since this is a point to point, normally, normally I would create static routes and I would be sending five, make sure that 5 dot 1 here, goes over the 10 0 1 dot 2 next hop. And I would do the same for 5 dot 2. Make sure it goes over the 10 0 0 2 2 next hop. And right here, we, even though we have a conflict here, we see that we are actually using appropriate next hops. Now let's say this is end point to point, right? Let's say this is a network where it's still a point to point, but it, we have multiple devices on this. Uh, it's basically layer two VLAN in which, maybe router two is a fail over for router one and all the servers here fill, fill over to here, but there's a couple of live servers here, and we just need everything to take this path, to be its primary for the 1 9 2 1 6 8 5 network. When we're talking about this, we're actually talking about costing. There's other ways to do this. E I G R P. It's increasing the distance, or certain other metrics for BGP. Same with rip. OSPF is costing. Now the way to go about this, is to go onto router two. So for here, we first have to make sure that router two currently has no extra cost and set up. Currently, there's no extra cost and setup for O S P F's so we don't have to worry about that. So let's go back to router three. For router three, let's take a look at the O S P F routing table. So here we can see the costing for everything, right? And let me move this to the side here so we can go over this. So for the cost to get to 1 9 2 1 6 8 5 is cost two from router three. It's always going to be cost two. Now to get to the computer networks here, the cost is going to be 11. So we have to make sure that whatever adjustment we make for fastEthernet one slash zero, it doesn't affect routers three's ability or router one's ability to get to the appropriate computer networks here. How do we go about this? The first thing we have to make sure on is, we have to make sure that the costing will always be at a point where router two will always be the primary for 1 9 2 1 6 8 1 2 dot 2 However, not be the primary for 1 9 2 1 6 8 5. So how do we do this? We do, We first adjust the costing for the 1 9 2 1 6 8 5 network. And since this costs two, we'll just make this be cost three. Now let's see how this works. All right, so that resolved one issue. So everything here looks fine. Now let's take a look at router one. Now, by increasing the costs for fastEthernet, one slash zero, we actually just made a pretty big impact on router one's ability to get to the 10 0 2 network here which is right there. Again, normally this wouldn't be an issue in a production environment, because this is all just for routing and normally wouldn't need to do any big access on this, but in this case, we're going to not have much of a choice and we'll try and resolve this here. So again, let's go back to router two, and we have that. So now we have to put in a cost that is going to make this be a lot less attractive, but not too unattractive for it to want to use the appropriate next hop for the 1 9 2 1 6 8 1 network. Because if I increase the cost anymore, uh, on F00, what's gonna happen is it's going to want to go through route three to reach, to, to reach PC two. We don't want that. So what I would do is increase the costs for F00 on router two. Now what number should I put in? Well, let's see here. The number here is currently 11, so let's try 12 for the cost. Okay. So let's see here, to get to the 10 0 2 network, it's going over the 10 0 1 which is what we want to get to the 10 0 0 0 network. It's also used in 10 0 1 1, which is what we want and to get to the 1 9 2 1 6 8 1 network it's used in 1 9 2 1 6 8 5 dot 2, which is exactly what we want. Let's just make sure router three is set up properly, and let's see if our router three could connect to 1 9 2 1 6 8 1 dot 2, it is currently using the correct next hop. So we are all set here. No issues on connecting to our appropriate devices. Everything's using the appropriate next hops. So we are all set. Thank you for listening.

Intermediate Provider : Matthew Mercaldi 3 Lessons · 14m in Arabic, German, English, Spanish, French, Portuguese, Chinese

Course Description

In this course, you will learn about the different network layers—L1, L2, and L3—and what sorts of network connectivity problems each layer can experience. From there we’ll cover MAC addresses and how they relate to IP addresses via address resolution protocols. You will also learn about how network interface cards function and their role in determining network speed.

We’ll provide an overview of hardware routing and explain how it connects to various sites from your computer. You’ll also learn about the device drivers needed to install network interface cards and the differences between generic and vendor-specific driver performance. By the end of this course, you’ll be able to tell when the hardware itself is what’s causing connectivity issues—and what to do about it.

What You'll Learn

Identify the connection between a MAC address and an IP address through address resolution protocols
Understand the purpose and function of network interface cards and their role in determining network speed
Distinguish the network layers L1, L2, and L3 and the connectivity problems each can experience
Explain how hardware routing connects your computer to various sites
Compare generic versus vendor-specific device driver performance when installing network interface cards
Recognize when network hardware itself is the cause of connectivity issues and what to do about it

Key Takeaways

Network connectivity problems can occur at different network layers (L1, L2, and L3), each with its own types of issues.
MAC addresses relate to IP addresses through address resolution protocols.
Network interface cards function in a way that helps determine network speed.
Hardware routing connects a computer to various sites.
The device drivers used to install network interface cards differ in performance between generic and vendor-specific drivers.

Frequently Asked Questions

What does this course cover?

It covers the network layers L1, L2, and L3 and the connectivity problems each can experience, MAC addresses and how they relate to IP addresses via address resolution protocols, how network interface cards function and their role in network speed, an overview of hardware routing, and the device drivers needed to install network interface cards including the differences between generic and vendor-specific driver performance.

What will I be able to do after completing this course?

By the end of the course you will be able to tell when the hardware itself is causing connectivity issues and what to do about it.

What lessons are included in this course?

The course includes three lessons: Route Path, Address Resolution Protocol, and Drivers and Network Interface Cards.

What skills does this course help build?

It builds skills in Network Connections, Network Interface, Network Layer, Network Troubleshooting, Networking Basics, and Networking Hardware.