Ethan and Holly continue their OSPF journey this week with OSPF Network Types. They discuss the two main OSPF network types used today: the broadcast and point to point networks. They also explain designated routers, backup designated routers, and when those are used and why. Lastly they discuss some soft skills – knowing your vendor... Read more »

Our OSPF series continues with a look at OSPF neighbor formation and related timers. We talk about the five major packet types that carry information among OSPF routers, how OSPF routers become neighbors, how they negotiate link-state database exchanges, keep-alive messages, and how they negotiate designated and backup routers when multiple devices are on the... Read more »

By popular request (and now that we have some other background topics covered) we start our series on the Open Shortest Path First (OSPF) routing protocol. We kick off the series with OSPF basics including Link State Advertisements, Link State Database, and other related essentials. We’ll explore additional OSPF topics over subsequent episodes. This week’s... Read more »

If you need to route in your network, you can program static routes into all your routing-capable devices. And this can work. But at some point, you’re probably going to want to switch to a dynamic routing protocol. On today’s N Is For Networking, Ethan and Holly discuss the differences between static and dynamic routes,... Read more »

What shape is your network? In other words, what is its topology? On today’s episode, we discover the different types of network topologies and designs used in the enterprise, data center, and service provider networks. We cover leaf/spine, hub and spoke, point to point, mesh, and others. We also talk about how topologies affect traffic... Read more »

Let’s explore four goals of network design: stability, speed, scalability, and security. These goals are based on Ethan’s experience designing, building, and operating networks. Network architects and design experts might have other objectives, and that’s fine, but these four goals are the basis of today’s episode. Ethan and Holly discuss why these four goals are... Read more »

We wanted to do an episode on SD-WAN, but realized we needed to set the stage for how wide-area networking developed. That’s why today’s episode is a history lesson of the Wide Area Network (WAN). We talk about how WANs emerged, public and private WANs, how WANs connect to LANs and data centers, the care... Read more »

On today’s show, we’re going to dig deeper into tunnels and explore some of the quirks and features of tunnels. This week we’ll discuss maximum transmission units (MTUs), maximum segment size, IP fragmentation and more.  Today’s bonus material is more RFCs – RFC 4821 and RFC 8899. Episode Links: What Is a Tunnel? – N... Read more »

Let’s dig into tunnels. While some network engineers may want to quibble, a tunnel is when you put one packet inside of another packet to carry it across a network (frames also come into the picture, so hold off on your follow-ups for now). On today’s N Is For Networking, Ethan and Holly explore this... Read more »

The Dynamic Host Configuration Protocol (DHCP) assigns an IP address to a host that joins a network, along with other information necessary for the host to communicate. DHCP also has more to it, so this week’s episode is meant to be a solid introduction to this essential network protocol. We first discuss what it is... Read more »