Using pexpect is pretty straightforward, but what about the situations, when we don’t know in what state the device, that we’re interacting with is? In such a scenario, we have to implement logic in our script that could handle different
Category: Operating system
Basic Cisco router automation workflow with pexpect
Network automation can take many forms depending on the technologies and environments. Sometimes though, we have to dive deep into low-level automation, where we can’t use REST API or other more-convenient technologies. In this article, we will take a brief
TCN impact on the MST topology
Topology changes in a spanning-tree domain are inevitable. But what actually happens, and what impact does it have on the environment? We will find it out in this article! Topology We will examine today’s scenarios on the 3-tier topology. We’ve
PVST and MST (in)compatibility
Spanning-tree protocol configurations can cause headaches among network engineers. Especially if we have mixed topology, with more than one STP implementation. In this article, we will look closer at the interoperability between the Cisco PVST and MST. Based on two
How to add and configure Nokia VSR VM in the GNS3
GNS3 is a powerful tool to simulate computer networks. Many images are ready to use right after the basic setup. However, sometimes we have to put in some more work to make everything work as expected. In this article, we
OSPF with BFD case study
While administrating the network, it’s important to think about high availability. If one network element goes down, the network can still operate properly after it’s converged. But how about the convergence time? It differs from one protocol to another, and
IPv6 tunneling over IPv4 GRE
As network engineers, sometimes we have to deal with unusual problems. One of them is when we have two isolated IPv6 network parts, but we want them to be able to communicate with each other. In this article, we’re gonna
Layer 3 MTU case study
In the previous article, I’ve touched the layer 2 MTU topic. This time, we will see how’s the behaviour of layer 3 MTU in 3 different scenarios. Packet structure First of all, before we touch on some case scenarios, let’s
Layer 2 MTU case study
The MTU topic seems to be confusing, especially among young network engineers. I’ve decided to into two parts. This article is focused on the layer 2 MTU aspect exclusively. I’ve prepared 3 case scenarios to present how’s switch behaves with
Basic layer 2 operations on Nokia SR-Linux
In this article, we will dive into a brand-new Nokia network operating system – SR-Linux, which is available on a Nokia 7220 series. We will focus mainly on the basic L2 operations on this platform. Topology The topology for this