If you’ve ever wondered what the difference is between a Switched Virtual Interface (SVI) and Integrated Routing and Bridging (IRB), today’s show is for you! Ethan Banks and Holly Metlitzky start with some history and the basics of communication between layer 2 and layer 3 and then explain how the concepts of SVI and IRB... Read more »

The job interview is an inescapable part of a career journey. Today on N Is For Networking, we conduct a mock interview with a candidate who’s applying for a junior network administration role. The goal is to give Toni Mrowetz, our candidate, feedback. At the same time, we hope this helps anyone listening who might... Read more »

We dive back into the world of IPsec with an episode dedicated to configuring IPsec tunnels. After discussing a listener comment regarding transport mode in IPsec tunnels, Ethan Banks and Holly Metlitzky work through topics such as multi-vendor IPsec configuration, licensing, and the details of configuration and routing. Bonus material: MTU size and NAT-T. Episode... Read more »

We got some interesting listener feedback from our series on OSPF, so today’s N Is for Networking is another “Well actually” episode where we dig into that feedback. In particular, we’ll cover a defense of OSPF multi-area deployments, and dig into OSPF LSA types. Episode Links: OSPF Basics – N Is For Networking Episode 38... Read more »

It’s time to talk crypto. No, not the Bitcoin kind. Ethan and Holly introduce the basics of IPsec, the protocol that authenticates and encrypts traffic between endpoints. They discuss what it is, how it provides trustworthiness and secrecy to IP traffic, and common use cases. They review the different types of IPsec protocols and modes,... Read more »

Ethan and Holly bring you the last installment of the OSPF series discussing OSPF area types. They discuss why OSPF areas exist, do a quick recap of what OSPF areas actually are, and then introduce the different types of OSPF areas.  Lastly, see if you can answer Ethan’s rapid-fire OSPF questions. Episode Transcript: This episode... Read more »

We ask listeners for follow up and you’ve sent it in. On today’s show we respond to listener comments and corrections on tunneling, the link aggregation control protocol, link aggregation in general, and DHCP options. We also talk about the network engineering certification journey. If you’ve got a “Well, actually” or any other follow up,... Read more »

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 »

This week we continue with DNS. In our last episode we covered the basics; today we expand our scope to cover topics such as security for DNS, reverse DNS, and DNS record types. For dessert this week, a serving of Raspberry Pi and Happy Eyeballs. Episode Links: DNS: Turning Names into Numbers – N Is... Read more »

The Domain Name System (DNS) keeps the Internet running. On today’s N Is For Networking podcast, we talk about how DNS transforms human-readable host names into IP addresses so that Internet traffic can be sent to the right place. We talk about root name servers, Top Level Domains (TLDs), and other elements of the DNS... Read more »

Following last week’s introduction to network monitoring, we discuss the Simple Network Management Protocol (SNMP), one of the most implemented types of network monitoring. We discuss how it is organized, operations that SNMP can perform, and versions of SNMP. This week’s bonus conversation is a discussion on the future for SNMP. Episode Links: MIB tree... Read more »