CCIE – STP 802.1D – Fundamentals

INTRODUCTION For resiliency purposes, Layer2 topologies are designed and deployed in a physical loop. Unlike the IP protocol which uses the TTL field as a built-in mechanism for preventing packets from looping endlessly through the network, the Ethernet protocol does not provide such facility and therefore, unless we can prevent a layer2 loop, the following problems would occur: Broadcast storms – endless broadcast of frames through the entire L2 domain Hosts end-up receiving duplicates frames from different switches Unstable mac-address tables due to continuous host mac address learning on different ports The STP (Spanning Tree Protocol) was developed to avoid…

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The OSI Model at Work

In this blog, I will explain the OSI model from a more pragmatic point of view. Doing so, I’m hoping to bring some of the abstract concepts to life.

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How to be a Good Troubleshooter?

Often, people would come to me with a technical escalation which is not actually technically difficult to resolve, rather technically misunderstood. So let’s see what it takes to overcome that.

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vSphere v5.5 :: Are SSD Disks Worth it?

When I first built my ESXi server, I thought I’d invest in a good server to allow me to really get my  hands “dirty” with VMware. When it came to acquiring disks, I quickly realise that SSD drives were very expensive … so I ended up with SAS drives. Didn’t take long to find out it is possible to optimise Memory Resources by using SSD drives. I have therefore decided to invest in two 128 GB SSD drives but never really got the chance to actually put them to test. I connected and used them as local storage. Recently, prices…

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