Flavio Bruno Leitner

Recent Posts

Open vSwitch without stale ports

Open vSwitch is growing every day and being used in large-scale deployments. Usually, that means there are few ports configured in the vswitch that will be always available, like physical Ethernet ports and several other ports providing networking connectivity to virtual machines or containers. Those other ports are software devices and very often they cannot be reused after a reboot or a system crash for example.

This blog post will talk about how to make sure the vSwitch comes up clean after a system crash or bad shutdown. The idea is that once vSwitch is up, there is no need for another component (usually a remote controller) to iterate over a large number of stale ports and clean them up.

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Tracing packets inside Open vSwitch

Open vSwitch is a software switch responsible for providing network connectivity to virtual machines or containers. Since it is programmable, it brings a challenge to understand what is going on in the network. Open vSwitch (OVS) is an OpenFlow virtual switch, so before talking about OVS itself, it is necessary to introduce OpenFlow a bit.

OpenFlow is an open standard protocol that allows separation of the packet forwarding (data plane) from the high level routing decisions (control plane). The control plane (also known as OF controller) is responsible to provide instructions to the data plane (vswitch) on how to process packets.

The fact that each packet can have its own fate brings a new challenge to understand what is going on in the network. This article will show how to know what is happening with packets inside the vswitch.

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Logging in Open vSwitch

Open vSwitch (OVS) is a virtual switch used in production from small to large scale deployments. It is designed to provide network automation along with support for a number of management interfaces and protocols.

However, the developer or the administrator might need to understand more of what is going on under the hoods and OVS does a good job providing a very good logging facility which is the subject of this article.

Editor’s note: Red Hat Knowledgebase – “What Red Hat products provide support for Open vSwitch?

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