STP and Graph Theory

Spanning Tree Protocol (STP) is one of several methods of avoiding loops in bridged local area networks. For most of us, working with the typical corporate LAN, STP is the default configuration of switches and it just works. But it may not always be the most efficient way to connect switches. This post looks at exactly what a spanning tree is, why it is used to solve the problem of loops in a network, and why it may not always be the most efficient way to do that.

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IEEE 802.1Q Bridges and Bridged Networks

I have been working recently on the design for an industrial network. The network runs through a physical tunnel, and so requires a ring topology to provide resilience against failure. Because the network may incorporate switches from different vendors I decided to read the current standard for this, the IEEE standard 802.1Q - 2014. This blog post aims to break down the idea of a bridged network to the lowest level, to reflect accurately what is in the standard.

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Docker Overlay Network Details

Docker Swarm uses an overlay network for communication between containers on different hosts, and for load balancing incoming traffic to a service. On Windows Server 2016 before Windows Update KB4015217 this overlay network is not supported. After KB4015217 the communication between containers works, but the routing mesh that load balances incoming traffic is not supported. Now with Windows Server 2016 version 1709 the routing mesh works as well. The purpose of this post is to take an in depth look at how the overlay network and the routing mesh work in practice.

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Docker Swarm Networking

Docker Swarm enables containers to operate together to provide a service, across different nodes in a cluster. It uses an overlay network for communication between containers on different hosts. It also supports a routing mesh, which load-balances and routes incoming connections to the containers. On Windows Server 2016 before the latest version this routing mesh is not supported. Now it is, with the release of version 1709, so we can see how it all works.

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