Note: This article is originally published here

In this article, I discuss external connectivity in Open Virtual Network (OVN), a subproject of Open vSwitch (OVS), using a distributed gateway router.

OVN provides external connectivity in two ways:

• A logical router with a distributed gateway port, which is referred to as a distributed gateway router in this article
• A logical gateway router

In this article, you will see how to create a distributed gateway router and an example of how it works.

Creating a distributed gateway router has some advantages over using a logical gateway router for the CMS (cloud management system):

• It is easier to create a distributed gateway router because the CMS doesn’t need to create a transit logical switch, which is needed for a logical gateway router.
• A distributed gateway router supports distributed north/south traffic, whereas the logical gateway router is centralized on a single gateway chassis.
• A distributed gateway router supports high availability.

Note: The CMS can be OpenStack, Red Hat OpenShift, Red Hat Virtualization, or any other system that manages a cloud.

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